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A076663 a(n) = sum of sigma(e) where e ranges over all non-divisors of n that are between 1 and n. 0

%I #3 Feb 11 2014 19:05:32

%S 0,0,3,4,14,13,32,30,51,59,86,72,126,129,154,163,219,205,276,262,326,

%T 355,406,361,484,504,546,561,659,622,761,737,840,883,944,900,1097,

%U 1112,1177,1160,1341,1300,1479,1465,1560,1658,1757,1645,1921,1928,2057,2085

%N a(n) = sum of sigma(e) where e ranges over all non-divisors of n that are between 1 and n.

%t f[n_] := Module[{s, i}, s = 0; For[i = 1, i < n, i++, If[Mod[n, i] != 0, s = s + DivisorSigma[1, i]]]; s]; Table[f[i], {i, 1, 100}]

%K nonn

%O 1,3

%A _Joseph L. Pe_, Oct 24 2002

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Last modified September 9 18:08 EDT 2024. Contains 375765 sequences. (Running on oeis4.)