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%I #10 Jul 25 2022 22:42:18
%S 0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,1,0,1,0,0,0,1,0,0,0,0,0,1,0,0,0,0,
%T 0,1,0,0,0,1,0,1,0,0,0,0,0,1,0,0,0,0,0,1,0,1,0,0,0,1,0,0,0,0,0,1,0,0,
%U 0,1,0,1,0,0,0,0,0,1,0,1,0,0,0,1,0,0,0,1,0,1,0,0,0,0,0,1,0,0,0,1,0,1,0,1,0,0,0,1,0,0,0,1,0,1,0,0,0,0,0,1
%N Characteristic function for abundant numbers (A005101): a(n) = 1 if A001065(n) > n, 0 otherwise.
%H Antti Karttunen, <a href="/A294937/b294937.txt">Table of n, a(n) for n = 1..16384</a>
%H <a href="/index/Ch#char_fns">Index entries for characteristic functions</a>.
%H <a href="/index/Su#sums_of_divisors">Index entries for sequences related to sums of divisors</a>.
%F a(n) = 1 if A033880(n) > 0, 0 otherwise.
%F a(n) = 1 - A294935(n).
%F Asymptotic mean: Limit_{m->oo} (1/m) * Sum_{k=1..m} a(k) = A302991. - _Amiram Eldar_, Jul 25 2022
%t a[n_] := If[DivisorSigma[1, n] > 2*n, 1, 0]; Array[a, 100] (* _Amiram Eldar_, Jul 25 2022 *)
%o (PARI) a(n) = sigma(n) > 2*n; \\ _Michel Marcus_, Jul 25 2022
%Y Cf. A001065, A033880, A294934, A294935, A294936, A302991.
%Y Cf. A005101 (positions of ones), A263837 (of zeros).
%K nonn
%O 1
%A _Antti Karttunen_, Nov 12 2017
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