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%I #11 Mar 14 2024 03:46:05
%S 1,1,1,1,1,1,1,1,1,1,1,0,1,1,1,1,1,0,1,0,1,1,1,0,1,1,1,1,1,0,1,1,1,1,
%T 1,0,1,1,1,0,1,0,1,1,1,1,1,0,1,1,1,1,1,0,1,0,1,1,1,0,1,1,1,1,1,0,1,1,
%U 1,0,1,0,1,1,1,1,1,0,1,0,1,1,1,0,1,1,1,0,1,0,1,1,1,1,1,0,1,1,1,0,1,0,1,0,1,1,1,0,1,1,1,0,1,0,1,1,1,1,1,0
%N Characteristic function for nonabundant numbers (A263837): a(n) = 1 if A001065(n) <= n, 0 otherwise.
%H Antti Karttunen, <a href="/A294935/b294935.txt">Table of n, a(n) for n = 1..65537</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 A033879(n) >= 0, 0 otherwise.
%F a(n) = 1 - A294937(n).
%t a[n_] := Boole[DivisorSigma[1, n] <= 2*n]; Array[a, 100] (* _Amiram Eldar_, Mar 14 2024 *)
%Y Cf. A001065, A033879, A294934, A294936, A294937.
%Y Cf. A263837 (positions of ones), A005101 (of zeros).
%K nonn
%O 1
%A _Antti Karttunen_, Nov 12 2017
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