This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A193336 #15 Mar 30 2024 03:01:49
%S A193336 0,0,6,0,8,24,14,0,0,26,24,48,16,56,56,0,26,0,36,64,62,78,56,144,0,64,
%T A193336 84,112,48,182,62,0,120,80,120,0,40,144,112,156,64,248,72,192,112,182,
%U A193336 120,192,0,0,182,114,80,336,182,336,180,156,144,448,64,248,196,0,192,390,108,208,248,390,182,0,76,160,192,288,248,448,180,256,0
%N A193336 Sum of even divisors of sigma(n).
%C A193336 sigma(n) = sum of divisors of n: A000203 (also called sigma_1(n)).
%H A193336 Antti Karttunen, <a href="/A193336/b193336.txt">Table of n, a(n) for n = 1..16384</a>
%H A193336 <a href="/index/Si#SIGMAN">Index entries for sequences related to sigma(n)</a>.
%H A193336 <a href="/index/Su#sums_of_divisors">Index entries for sequences related to sums of divisors</a>.
%F A193336 a(n) + A193337(n) = A051027(n). - _Antti Karttunen_, Nov 18 2017
%F A193336 From _Amiram Eldar_, Mar 30 2024: (Start)
%F A193336 a(n) = A146076(A000203(n)).
%F A193336 a(n) = 0 if and only if n is in A028982. (End)
%e A193336 a(14) = 56 because sigma(14) = 24 and the sum of the 6 even divisors {2, 4, 6, 8, 12, 24} is 56.
%t A193336 Table[Total[Select[Divisors[DivisorSigma[1,n]], EvenQ[ # ]&]], {n, 53}]
%o A193336 (PARI) A193336(n) = { my(s=sigma(n)); sumdiv(s,d,(!(d%2))*d); }; \\ _Antti Karttunen_, Nov 18 2017
%Y A193336 Cf. A000203, A028982, A051027, A146076, A193334, A193337.
%K A193336 nonn
%O A193336 1,3
%A A193336 _Michel Lagneau_, Jul 23 2011
%E A193336 More terms from _Antti Karttunen_, Nov 18 2017