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A015917
Numbers k such that sigma(k) + 12 = sigma(k+12).
19
5, 7, 11, 17, 19, 29, 31, 41, 47, 59, 61, 65, 67, 71, 89, 97, 101, 127, 137, 139, 151, 167, 170, 179, 181, 199, 209, 211, 227, 229, 239, 251, 257, 269, 271, 281, 337, 347, 367, 389, 397, 409, 419, 421, 431, 449, 467, 479, 487, 491, 509, 557, 587
OFFSET
1,1
LINKS
MATHEMATICA
Select[Range[600], DivisorSigma[1, #]+12==DivisorSigma[1, #+12]&] (* Harvey P. Dale, Oct 14 2012 *)
PROG
(PARI) is(n)=sigma(n)+12==sigma(n+12) \\ Charles R Greathouse IV, Mar 09 2014
CROSSREFS
Cf. A000203.
Union of A046133 and A054902.
Sequence in context: A110016 A254672 A056775 * A046133 A086136 A136052
KEYWORD
nonn
STATUS
approved