|
%I #10 Aug 15 2015 09:00:02
%S 28,39,42,60,72,91,90,96,124,120,120,168,144,144,195,168,186,224,180,
%T 234,252,217,216,210,280,248,240,360,312,336,288,336,403,372,392,378,
%U 363,480,360,372,546,384,508,399,468,465,504,434,576,600,504,456,504,560
%N Sum of divisors (A000203) of abundant numbers (A005101).
%H Harvey P. Dale, <a href="/A204822/b204822.txt">Table of n, a(n) for n = 1..1000</a>
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/AbundantNumber.html">Abundant Number</a>
%F a(n) = A000203(A005101(n)) = A005101(n) + A205098(n).
%F a(n) << n log log n with lim sup a(n)/(n log log n) approximately 7.192. - _Charles R Greathouse IV_, Feb 19 2013
%t sdan[n_]:=Module[{ds=DivisorSigma[1,n]},If[ds>2n,ds,0]]; Select[ Array[ sdan, 300],#>0&] (* _Harvey P. Dale_, Aug 15 2015 *)
%o (PARI) for(n=6,200,s=sigma(n);if(s>2*n,print1(s", "))) \\ _Charles R Greathouse IV_, Feb 19 2013
%Y Cf. A204823 (sum of divisors of deficient numbers), A205098 (sum of proper divisors of abundant numbers).
%K nonn
%O 1,1
%A _Jaroslav Krizek_, Jan 22 2012
|
