A015914 Numbers k such that sigma(k) + 6 = sigma(k+6).

5, 7, 11, 13, 17, 23, 31, 37, 41, 47, 53, 61, 67, 73, 83, 97, 101, 103, 104, 107, 131, 147, 151, 157, 167, 173, 191, 193, 223, 227, 233, 251, 257, 263, 271, 277, 307, 311, 331, 347, 353, 367, 373, 383, 433, 443, 457, 461, 503, 541, 557, 563, 571

Offset: 1

Author

Robert G. Wilson v

Keywords

• nonn

Links

• Reinhard Zumkeller, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A000203.

See A054903 for nonprimes. - Reinhard Zumkeller, Jan 27 2009

Programs

Mathematica

Select[Range[50000], DivisorSigma[1, #] + 6==DivisorSigma[1, # + 6] &] (* Vincenzo Librandi, Mar 10 2014 *)