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%I #26 Aug 04 2023 15:47:05
%S 3,6,7,11,12,14,15,19,21,22,23,24,27,28,30,31,33,35,38,39,42,43,44,46,
%T 47,48,51,54,55,56,57,59,60,62,63,65,66,67,69,70,71,75,76,77,78,79,83,
%U 84,85,86,87,88,91,92,93,94,95,96,99,102,103,105,107,108,110,111,112,114,115,118
%N Numbers whose sum of divisors (A000203) is divisible by 4.
%C A subsequence of A028983 (even sum of divisors) which contains all numbers but the squares and twice the squares, so no term of this sequence is of that form, either.
%C Any number having at least two odd prime factors to an odd power is in this sequence, therefore it has asymptotic density 1. - _M. F. Hasler_, Apr 26 2017
%H Amiram Eldar, <a href="/A248150/b248150.txt">Table of n, a(n) for n = 1..10000</a>
%F a(n) ~ n. - _Charles R Greathouse IV_, Sep 01 2015
%t Select[Range[200],Divisible[DivisorSigma[1,#],4]&] (* _Harvey P. Dale_, Feb 20 2015 *)
%o (PARI) for(n=1,999,sigma(n)%4||print1(n","))
%Y Cf. A000203, A028982, A028983, A248151.
%Y First differs from A022544 by including 65.
%K nonn
%O 1,1
%A _M. F. Hasler_, Oct 02 2014
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