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Sum of proper divisors (A001065) of abundant numbers (A005101).
3

%I #15 Mar 11 2024 04:15:40

%S 16,21,22,36,42,55,50,54,76,66,64,108,78,74,123,90,106,140,92,144,156,

%T 117,114,106,172,136,126,240,186,204,150,196,259,222,236,218,201,312,

%U 186,196,366,198,316,203,270,265,300,226,366,384,284,234,280,332,312

%N Sum of proper divisors (A001065) of abundant numbers (A005101).

%H Amiram Eldar, <a href="/A205098/b205098.txt">Table of n, a(n) for n = 1..10000</a>

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/AbundantNumber.html">Abundant Number</a>.

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/RestrictedDivisorFunction.html">Restricted Divisor Function</a>.

%F a(n) = A001065(A005101(n)) = A204822(n) - A005101(n).

%t f[n_] := Module[{s = DivisorSigma[1, n] - n}, If[s > n, s, Nothing]]; Array[f, 250] (* _Amiram Eldar_, Mar 11 2024 *)

%Y Cf. A205099 (sum of proper divisors of deficient numbers), A204822 (sum of divisors of abundant numbers), A001065, A005101.

%K nonn

%O 1,1

%A _Jaroslav Krizek_, Jan 22 2012