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A171265 Primes of the form 1 + 6-multiperfect numbers. 4

%I #7 Sep 19 2013 03:19:59

%S 9186050031556349952001,837294585717161066223413745156096001,

%T 102833200965458113792221682653890347008001,

%U 8564360335859979576063023115658227351552001

%N Primes of the form 1 + 6-multiperfect numbers.

%C 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),

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

%C 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.

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

%Y Cf. A046061, A093034, A171263, A171264.

%K fini,nonn

%O 1,1

%A _M. F. Hasler_ and _Farideh Firoozbakht_, Apr 15 2010

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Last modified April 25 01:35 EDT 2024. Contains 371964 sequences. (Running on oeis4.)