A200922 Least k such that (3^n - k)*3^n - 1 is a prime number.

1, 1, 1, 3, 7, 1, 1, 13, 17, 17, 7, 43, 25, 3, 41, 29, 57, 11, 21, 1, 25, 29, 17, 27, 15, 7, 11, 63, 15, 237, 73, 21, 43, 229, 1, 1, 73, 3, 253, 63, 7, 179, 3, 289, 97, 157, 7, 59, 95, 237, 33, 47, 3, 31, 43, 141, 157, 63, 137, 101, 387, 109, 157, 27, 29, 37

Offset

1,4

Links

Table of n, a(n) for n=1..66.

Mathematica

Table[k = 0; While[!PrimeQ[(3^n - k)*3^n - 1], k++]; k, {n, 72}]

Crossrefs

Cf. A191617, A191618, A191619, A191620,A200920, A200921, A200923.

Sequence in context: A200235 A127929 A228147 * A210453 A003118 A096409

Adjacent sequences: A200919 A200920 A200921 * A200923 A200924 A200925

Keyword

nonn

Author

Michel Lagneau, Nov 24 2011

Status

approved