A172997 Numbers n such that for p=prime(n), (2p-1)^(2p-1) mod 2^(2p-1) is prime.

1, 5, 6, 8, 34, 131

Offset

1,2

Links

Table of n, a(n) for n=1..6.

Example

5 is in the sequence, since prime(5)=11 and (2*11-1)^(2*11-1) mod 2^(2*11-1) = 21^21 mod 2^21 = 1472837 is prime.

Crossrefs

Cf. A000040, A000079, A000312, A178537, A178966.

Sequence in context: A134077 A120128 A019149 * A244274 A279664 A230461

Adjacent sequences: A172994 A172995 A172996 * A172998 A172999 A173000

Keyword

nonn

Author

Juri-Stepan Gerasimov, Jan 01 2011

Status

approved