A067831 Primes p such that sigma(p-6) < p.

7, 11, 13, 17, 19, 23, 29, 37, 43, 47, 53, 59, 67, 73, 79, 89, 103, 107, 109, 113, 137, 157, 163, 173, 179, 197, 199, 229, 233, 239, 257, 263, 269, 277, 283, 313, 317, 337, 353, 359, 373, 379, 389, 439, 449, 463, 467, 509, 547, 563, 569, 577, 593, 599, 607

Offset: 1

Author

Benoit Cloitre, Feb 08 2002

Keywords

• nonn

Comments

Superset of A046117. - R. J. Mathar, Sep 30 2008

Links

• Amiram Eldar, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A000203, A046117, A067832.

Programs

Mathematica

Select[Prime[Range[4,200]],DivisorSigma[1,#-6]<#&] (* Harvey P. Dale, Aug 10 2023 *)

PARI

isok(p) = p > 6 && isprime(p) && sigma(p-6) < p; \\ Amiram Eldar, Apr 24 2025