A246809 Composite numbers such that n^(b^n) == (-1)^b (mod C_b(n)), where C_b(n) = n*b^n+1 (A210339).

12801, 136497879001, 422240040001, 18677955240001

Offset

1,1

Links

Table of n, a(n) for n=1..4.

J. M. Grau and A. M. Oller-Marcen, An O(log^2(N)) time primality test for generalized Cullen numbers, Math. Comp., Vol. 80, Num. 276 (2011), 2315-2323.

Crossrefs

Cf. A210339.

Sequence in context: A157509 A035916 A243050 * A204490 A218457 A251053

Adjacent sequences: A246806 A246807 A246808 * A246810 A246811 A246812

Keyword

nonn,hard,more

Author

Felix Fröhlich, Nov 16 2014

Status

approved