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A204822 Sum of divisors (A000203) of abundant numbers (A005101). 4
28, 39, 42, 60, 72, 91, 90, 96, 124, 120, 120, 168, 144, 144, 195, 168, 186, 224, 180, 234, 252, 217, 216, 210, 280, 248, 240, 360, 312, 336, 288, 336, 403, 372, 392, 378, 363, 480, 360, 372, 546, 384, 508, 399, 468, 465, 504, 434, 576, 600, 504, 456, 504, 560 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
Eric Weisstein's World of Mathematics, Abundant Number
FORMULA
a(n) = A000203(A005101(n)) = A005101(n) + A205098(n).
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
MATHEMATICA
sdan[n_]:=Module[{ds=DivisorSigma[1, n]}, If[ds>2n, ds, 0]]; Select[ Array[ sdan, 300], #>0&] (* Harvey P. Dale, Aug 15 2015 *)
PROG
(PARI) for(n=6, 200, s=sigma(n); if(s>2*n, print1(s", "))) \\ Charles R Greathouse IV, Feb 19 2013
CROSSREFS
Cf. A204823 (sum of divisors of deficient numbers), A205098 (sum of proper divisors of abundant numbers).
Sequence in context: A080983 A179105 A096430 * A179166 A034964 A195897
KEYWORD
nonn
AUTHOR
Jaroslav Krizek, Jan 22 2012
STATUS
approved

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Last modified February 26 22:44 EST 2024. Contains 370354 sequences. (Running on oeis4.)