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A015865 Numbers n such that sigma(n) = sigma(n + 5). 16
6, 46, 1030, 2673, 4738, 4785, 10437, 14025, 20038, 20326, 23914, 28702, 31101, 39273, 39669, 41349, 41554, 44709, 46366, 55918, 68638, 74205, 93682, 94365, 96790, 103678, 115245, 115642, 124785, 169990, 182830, 185073, 207118, 214090 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Donovan Johnson, Table of n, a(n) for n = 1..1000

MAPLE

A015865:=proc(q) local n;

for n from 1 to q do if sigma(n+5)=sigma(n) then print(n); fi; od; end:

A015865 (10^10); # Paolo P. Lava, Mar 25 2013

MATHEMATICA

Select[Range[215000], DivisorSigma[1, #]==DivisorSigma[1, # + 5] &] (* Vincenzo Librandi, Mar 10 2014 *)

PROG

(PARI) is(n)=sigma(n)==sigma(n+5) \\ Charles R Greathouse IV, Mar 09 2014

CROSSREFS

Cf. A002961, A007373, A015861, A015863, A015866, A015867, A015876, A015877, A015880, A015881, A015882, A015883, A181647.

Sequence in context: A275031 A094655 A327364 * A276271 A145506 A256160

Adjacent sequences:  A015862 A015863 A015864 * A015866 A015867 A015868

KEYWORD

nonn

AUTHOR

Robert G. Wilson v

EXTENSIONS

Corrected and extended by T. D. Noe, Oct 31 2006

STATUS

approved

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Last modified April 9 12:51 EDT 2020. Contains 333352 sequences. (Running on oeis4.)