Speaking of patterns...I use this method to see if I can spot anything.
import decimal
import secp256k1 as ice
def calculate_puzzle66_parts():
start = decimal.Decimal("36893488147419103231")
end = decimal.Decimal("73786976294838206463")
step = (end - start) / 16
for i in range(16):
decimal_num = start + (i + 1) * step - 1
hex_value = "%064x" % int(decimal_num)
wif_compressed = ice.btc_pvk_to_wif(hex_value)
print(f"Part {i + 1} Start point dec:", decimal_num)
print(f"Part {i + 1} Start point WIF:", wif_compressed)
quarter_dec = start + (i + 1) * step // 4
quarter_hex = "%064x" % int(quarter_dec)
wif_quarter = ice.btc_pvk_to_wif(quarter_hex)
print(f"Part {i + 1} 1/4 dec from 66:", quarter_dec)
print(f"Part {i + 1} 1/4 WIF from 66:", wif_quarter)
half_dec = start + (i + 1) * step // 2
half_hex = "%064x" % int(half_dec)
wif_half = ice.btc_pvk_to_wif(half_hex)
print(f"Part {i + 1} 1/2 dec from 66:", half_dec)
print(f"Part {i + 1} 1/2 WIF from 66:", wif_half)
three_quarter_dec = start + (i + 1) * step * 3 // 4
three_quarter_hex = "%064x" % int(three_quarter_dec)
wif_three_quarter = ice.btc_pvk_to_wif(three_quarter_hex)
print(f"Part {i + 1} 3/4 dec from 66:", three_quarter_dec)
print(f"Part {i + 1} 3/4 WIF from 66:", wif_three_quarter)
print(f"Part {i + 1} End point dec:", start + (i + 1) * step)
print(f"Part {i + 1} End point WIF:", ice.btc_pvk_to_wif("%064x" % int(start + (i + 1) * step)), "\n")
if __name__ == "__main__":
calculate_puzzle66_parts()
Part 1 Start point dec: 39199331156632797182
Part 1 Start point WIF: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZWzeyikXcEhFs6rMa1V
Part 1 1/4 dec from 66: 37469948899722526719
Part 1 1/4 WIF from 66: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZUziJujmDznaXnGPQSV
Part 1 1/2 dec from 66: 38046409652025950207
Part 1 1/2 WIF from 66: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZVfMsBQggk69993Lj3p
Part 1 3/4 dec from 66: 38622870404329373695
Part 1 3/4 WIF from 66: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZWL1RT5c9VPhkZ8H9oW
Part 1 End point dec: 39199331156632797183
Part 1 End point WIF: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZWzeyikXcEhGMwnHdn7
Part 2 Start point dec: 41505174165846491134
Part 2 Start point WIF: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZZfFCoSDTDuWJc1i5sr
Part 2 1/4 dec from 66: 38046409652025950207
Part 2 1/4 WIF from 66: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZVfMsBQggk69993Lj3p
Part 2 1/2 dec from 66: 39199331156632797183
Part 2 1/2 WIF from 66: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZWzeyikXcEhGMwnHdn7
Part 2 3/4 dec from 66: 40352252661239644159
Part 2 3/4 WIF from 66: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZYKx6G6NXjJPak7TotN
Part 2 End point dec: 41505174165846491135
Part 2 End point WIF: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZZfFCoSDTDuWoVrghLp
Part 3 Start point dec: 43811017175060185086
Part 3 Start point WIF: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZcKqRt7uJD7kk9AvAt8
Part 3 1/4 dec from 66: 38622870404329373695
Part 3 1/4 WIF from 66: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZWL1RT5c9VPhkZ8H9oW
Part 3 1/2 dec from 66: 40352252661239644159
Part 3 1/2 WIF from 66: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZYKx6G6NXjJPak7TotN
Part 3 3/4 dec from 66: 42081634918149914623
Part 3 3/4 WIF from 66: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZaKtm578uyD5QqCf8om
Part 3 End point dec: 43811017175060185087
Part 3 End point WIF: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZcKqRt7uJD7mF4zwEkF
Part 4 Start point dec: 46116860184273879038
Part 4 Start point WIF: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZezRexob9CL1BfTmF23
Part 4 1/4 dec from 66: 39199331156632797183
Part 4 1/4 WIF from 66: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZWzeyikXcEhGMwnHdn7
Part 4 1/2 dec from 66: 41505174165846491135
Part 4 1/2 WIF from 66: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZZfFCoSDTDuWoVrghLp
Part 4 3/4 dec from 66: 43811017175060185087
Part 4 3/4 WIF from 66: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZcKqRt7uJD7mF4zwEkF
Part 4 End point dec: 46116860184273879039
Part 4 End point WIF: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZezRexob9CL1gZKDxzH
Part 5 Start point dec: 48422703193487572990
Part 5 Start point WIF: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZhf1t3VGzBYFdHuq1cQ
Part 5 1/4 dec from 66: 39775791908936220671
Part 5 1/4 WIF from 66: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZXfJXzRT4yzpyMhSS32
Part 5 1/2 dec from 66: 42658095670453338111
Part 5 1/2 WIF from 66: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZazYKLn4NiWe2KmF7j8
Part 5 3/4 dec from 66: 45540399431970455551
Part 5 3/4 WIF from 66: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZeKn6h8fgT2T5BG1zyQ
Part 5 End point dec: 48422703193487572991
Part 5 End point WIF: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZhf1t3VGzBYG87a7NRw
Part 6 Start point dec: 50728546202701266942
Part 6 Start point WIF: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZkKc78AxqAkW4otaiui
Part 6 1/4 dec from 66: 40352252661239644159
Part 6 1/4 WIF from 66: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZYKx6G6NXjJPak7TotN
Part 6 1/2 dec from 66: 43811017175060185087
Part 6 1/2 WIF from 66: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZcKqRt7uJD7mF4zwEkF
Part 6 3/4 dec from 66: 47269781688880726015
Part 6 3/4 WIF from 66: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZgKimW9S4gw8uNS9xwk
Part 6 End point dec: 50728546202701266943
Part 6 End point WIF: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZkKc78AxqAkWZdisLwg
Part 7 Start point dec: 53034389211914960894
Part 7 Start point WIF: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZnzCLCreg9xkWGorWC6
Part 7 1/4 dec from 66: 40928713413543067647
Part 7 1/4 WIF from 66: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZYzbeXmHzUbxC59ow7z
Part 7 1/2 dec from 66: 44963938679667032063
Part 7 1/2 WIF from 66: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZdf8YRTkDhitTp71pAW
Part 7 3/4 dec from 66: 48999163945790996479
Part 7 3/4 WIF from 66: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZiKfSKACSvqpjW95JbD
Part 7 End point dec: 53034389211914960895
Part 7 End point WIF: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZnzCLCreg9xm1FxSeJp
Part 8 Start point dec: 55340232221128654846
Part 8 Start point WIF: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZqenZHYLX9AzwtzyNbB
Part 8 1/4 dec from 66: 41505174165846491135
Part 8 1/4 WIF from 66: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZZfFCoSDTDuWoVrghLp
Part 8 1/2 dec from 66: 46116860184273879039
Part 8 1/2 WIF from 66: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZezRexob9CL1gZKDxzH
Part 8 3/4 dec from 66: 50728546202701266943
Part 8 3/4 WIF from 66: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZkKc78AxqAkWZdisLwg
Part 8 End point dec: 55340232221128654847
Part 8 End point WIF: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZqenZHYLX9B1Sh6RD2t
Part 9 Start point dec: 57646075230342348798
Part 9 Start point WIF: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZtKNnNE2N8PFPMTB21Z
Part 9 1/4 dec from 66: 42081634918149914623
Part 9 1/4 WIF from 66: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZaKtm578uyD5QqCf8om
Part 9 1/2 dec from 66: 47269781688880726015
Part 9 1/2 WIF from 66: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZgKimW9S4gw8uNS9xwk
Part 9 3/4 dec from 66: 52457928459611537407
Part 9 3/4 WIF from 66: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZnKYmwBjDQfCPra6THT
Part 9 End point dec: 57646075230342348799
Part 9 End point WIF: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZtKNnNE2N8PFtGjKJj8
Part 10 Start point dec: 59951918239556042750
Part 10 Start point WIF: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZvyy1SuiD7bVpxgmdfN
Part 10 1/4 dec from 66: 42658095670453338111
Part 10 1/4 WIF from 66: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZazYKLn4NiWe2KmF7j8
Part 10 1/2 dec from 66: 48422703193487572991
Part 10 1/2 WIF from 66: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZhf1t3VGzBYG87a7NRw
Part 10 3/4 dec from 66: 54187310716521807871
Part 10 3/4 WIF from 66: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZpKVSkCVbeZtE1H9iQ8
Part 10 End point dec: 59951918239556042751
Part 10 End point WIF: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZvyy1SuiD7bWKqCb6cT
Part 11 Start point dec: 62257761248769736702
Part 11 Start point WIF: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZyeZEXbQ46okGY7gWo9
Part 11 1/4 dec from 66: 43234556422756761599
Part 11 1/4 WIF from 66: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZbfBscSyqTpCdf9Admy
Part 11 1/2 dec from 66: 49575624698094419967
Part 11 1/2 WIF from 66: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZizJzaq7ug9PLvewANu
Part 11 3/4 dec from 66: 55916692973432078335
Part 11 3/4 WIF from 66: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZrKS7ZDFytUa4BmMTS9
Part 11 End point dec: 62257761248769736703
Part 11 End point WIF: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZyeZEXbQ46okmPYKfxL
Part 12 Start point dec: 64563604257983430654
Part 12 Start point WIF: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qa2K9TcH5u61zi2oYhET
Part 12 1/4 dec from 66: 43811017175060185087
Part 12 1/4 WIF from 66: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZcKqRt7uJD7mF4zwEkF
Part 12 1/2 dec from 66: 50728546202701266943
Part 12 1/2 WIF from 66: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZkKc78AxqAkWZdisLwg
Part 12 3/4 dec from 66: 57646075230342348799
Part 12 3/4 WIF from 66: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZtKNnNE2N8PFtGjKJj8
Part 12 End point dec: 64563604257983430655
Part 12 End point WIF: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qa2K9TcH5u621CsjkSLq
Part 13 Start point dec: 66869447267197124606
Part 13 Start point WIF: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qa4yjggxmk5EF9cf1wrW
Part 13 1/4 dec from 66: 44387477927363608575
Part 13 1/4 WIF from 66: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZczUz9npkxRKrQ27nPS
Part 13 1/2 dec from 66: 51881467707308113919
Part 13 1/2 WIF from 66: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZmeuDfWokfMdnPcTtgB
Part 13 3/4 dec from 66: 59375457487252619263
Part 13 3/4 WIF from 66: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZvKKTBEnkNHwiSqAUkY
Part 13 End point dec: 66869447267197124607
Part 13 End point WIF: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qa4yjggxmk5EFeVWWKPF
Part 14 Start point dec: 69175290276410818558
Part 14 Start point WIF: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qa7eKumeTb4SVb6skSxw
Part 14 1/4 dec from 66: 44963938679667032063
Part 14 1/4 WIF from 66: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZdf8YRTkDhitTp71pAW
Part 14 1/2 dec from 66: 53034389211914960895
Part 14 1/2 WIF from 66: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZnzCLCreg9xm1FxSeJp
Part 14 3/4 dec from 66: 61104839744162889727
Part 14 3/4 WIF from 66: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZxKG7zFZ8cCdYZASpQa
Part 14 End point dec: 69175290276410818559
Part 14 End point WIF: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qa7eKumeTb4SW635PmjP
Part 15 Start point dec: 71481133285624512510
Part 15 Start point WIF: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qaAJv8rL9S3ek2d8DWnX
Part 15 1/4 dec from 66: 45540399431970455551
Part 15 1/4 WIF from 66: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZeKn6h8fgT2T5BG1zyQ
Part 15 1/2 dec from 66: 54187310716521807871
Part 15 1/2 WIF from 66: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZpKVSkCVbeZtE1H9iQ8
Part 15 3/4 dec from 66: 62834222001073160191
Part 15 3/4 WIF from 66: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZzKCnoGKWr7KNn5yNok
Part 15 End point dec: 71481133285624512511
Part 15 End point WIF: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qaAJv8rL9S3ekXXbZqcM
Part 16 Start point dec: 73786976294838206462
Part 16 Start point WIF: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qaCyWMw1qH2rzUAU5Hx5
Part 16 1/4 dec from 66: 46116860184273879039
Part 16 1/4 WIF from 66: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZezRexob9CL1gZKDxzH
Part 16 1/2 dec from 66: 55340232221128654847
Part 16 1/2 WIF from 66: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qZqenZHYLX9B1Sh6RD2t
Part 16 3/4 dec from 66: 64563604257983430655
Part 16 3/4 WIF from 66: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qa2K9TcH5u621CsjkSLq
Part 16 End point dec: 73786976294838206463
Part 16 End point WIF: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qaCyWMw1qH2rzy6joVM6
-------------------------------------------------------------------------------------------------------------
But nothing. Just a glass ball, pure luck or brute force...