1,1

A simpler version of A179945, added at the request of the editor-in-chief.

Table of n, a(n) for n=1..51.

(PARI) is(n)=my(s=sigma(n)); isprime(s-n-1) && isprime(s-n-n-1) \\ Charles R Greathouse IV, Feb 19 2013

Subsequence of A179945.

Sequence in context: A214195 A308127 A091454 * A296717 A302753 A179945

Adjacent sequences: A175724 A175725 A175726 * A175728 A175729 A175730

nonn

Max Alekseyev, Aug 18 2010

Edited by N. J. A. Sloane, Aug 28 2010

approved