A201456 Least k such that (7^n + k)*7^n + 1 is a prime number.
3, 3, 9, 9, 3, 3, 51, 57, 101, 5, 23, 59, 51, 161, 3, 5, 93, 135, 41, 29, 57, 5, 111, 129, 113, 35, 11, 15, 107, 129, 167, 21, 11, 143, 261, 57, 137, 113, 203, 219, 53, 101, 263, 137, 309, 101, 261, 87, 99, 239, 369, 59, 123, 83, 3, 275, 227, 321, 221, 27, 81, 135, 57, 29, 17, 281, 71, 359, 27, 395, 261, 99, 21, 215, 323, 71, 63, 29
Offset: 1
Keywords
Programs
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Mathematica
Table[k = 0; While[!PrimeQ[(7^n + k)*7^n + 1], k++]; k, {n, 85}]