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A226361
Numbers n such that sigma(n) = sigma(n+1) + sigma(n+2).
4
378624, 661152, 5479092, 5526024, 7179624, 18744216, 122321970, 168201288, 215676636, 778701984, 1482154170, 1788138780, 1974360132, 2288979096, 3361923780, 4214315484, 4757106144, 4971510492, 6264306144, 6884356716, 10730488296, 11375549304, 16851779736
OFFSET
1,1
LINKS
Giovanni Resta, Table of n, a(n) for n = 1..88 (terms < 10^13)
MATHEMATICA
nn = 10^7; t = {}; sig0 = 1; sig1 = 3; Do[sig2 = DivisorSigma[1, n + 2]; If[sig0 == sig1 + sig2, AppendTo[t, n]]; sig0 = sig1; sig1 = sig2, {n, nn}]; t (* T. D. Noe, Jun 05 2013 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Alex Ratushnyak, Jun 05 2013
EXTENSIONS
a(17)-a(23) from Donovan Johnson, Jun 05 2013
STATUS
approved