A171265 Primes of the form 1 + 6-multiperfect numbers.

9186050031556349952001, 837294585717161066223413745156096001, 102833200965458113792221682653890347008001, 8564360335859979576063023115658227351552001

Offset: 1

Author

M. F. Hasler and Farideh Firoozbakht, Apr 15 2010

Keywords

• fini
• nonn

Comments

Primes of the form 1+A046061(n). A subsequence of A093034. This sequence has only 8 terms. a(5)=1+A046061(76),a(6)=1+A046061(79),

a(7)=1+A046061(204) and a(8)=1+A046061(209).

If p is a term of this sequence then for each positive integer k, x=p^k is a solution for the equation sigma(phi(x))=6(x-1). See comment lines of the sequence A093034.

Examples

			p=9186050031556349952001 is prime and sigma(p-1)/(p-1)=6, so p is in the sequence.
		

Crossrefs

Cf. A046061, A093034, A171263, A171264.