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%I #24 Apr 04 2022 15:25:37
%S 0,0,0,0,0,1,0,0,0,0,0,1,0,0,0,0,0,1,0,1,0,0,0,1,0,0,0,1,0,1,0,0,0,0,
%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 nondeficient numbers (A023196): a(n) = 1 if A001065(n) >= n, 0 otherwise.
%C Differs from A210455 for the first time at n=70, and after that at n=836, 4030, 5830, 7192, 7912, 9272, etc., that is, at weird numbers, A006037.
%C Differs from A336835 for the first time at n=120. - _Antti Karttunen_, Apr 04 2022
%H Antti Karttunen, <a href="/A294936/b294936.txt">Table of n, a(n) for n = 1..100000</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 - A294934(n).
%F a(n) >= A210455(n).
%F a(n) >= A341619(n). - _Antti Karttunen_, Apr 04 2022
%e The proper divisors of 6 are 1, 2 and 3, and their sum is 6, and because 6 >= 6, a(6) = 1.
%e The proper divisors of 70 are 1, 2, 5, 7, 10, 14, and 35, and their sum is 74, and because 74 >= 70, a(70) = 1.
%t Table[If[DivisorSigma[1,n]>=2n,1,0],{n,120}] (* _Harvey P. Dale_, Mar 22 2020 *)
%o (PARI) a(n) = sigma(n, -1)>=2 \\ _Felix Fröhlich_, Nov 12 2017
%Y Cf. A001065, A006037, A033880, A210455, A294887, A294934, A294935, A294937, A336835.
%Y Cf. A023196 (positions of ones), A005100 (of zeros), A341620 (inverse Möbius transform), A294927 [= A341620(n)-a(n)], A341619.
%K nonn
%O 1
%A _Antti Karttunen_, Nov 12 2017
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