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

1,1

Links

Table of n, a(n) for n=1..78.

Mathematica

 Table[k = 0; While[!PrimeQ[(7^n + k)*7^n + 1], k++]; k, {n, 85}]

Crossrefs

Cf. A191617, A200920, A201133.

Sequence in context: A362046 A155686 A290300 * A347033 A336992 A349673

Adjacent sequences: A201453 A201454 A201455 * A201457 A201458 A201459

Keyword

nonn

Author

Michel Lagneau, Dec 01 2011

Status

approved