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 A378995 #19 Dec 14 2024 05:25:40
%S A378995 3,7,2,15,9,7,12,31,13,21,18,5,21,2,12,63,27,91,30,9,16,21,36,31,93,
%T A378995 49,20,15,45,14,48,127,24,63,72,65,57,35,28,93,63,8,66,45,13,42,72,21,
%U A378995 171,217,36,105,81,70,108,31,40,105,90,3,93,56,52,255,126,28,102,135,48,12,108,403,111,133,62,75,144,98,120
%N A378995 Numerator of sigma(2*n)/(2*n).
%H A378995 Antti Karttunen, <a href="/A378995/b378995.txt">Table of n, a(n) for n = 1..32769</a>
%H A378995 <a href="/index/Si#SIGMAN">Index entries for sequences related to sigma(n)</a>.
%F A378995 a(n) = A017665(2*n).
%F A378995 a(n) = A062731(n) / A378994(n).
%F A378995 Asymptotic mean: Limit_{m->oo} (1/m) * Sum_{k=1..m} a(k)/A378996(k) = 5*Pi^2/24 (= 10 * A245058). - _Amiram Eldar_, Dec 14 2024
%t A378995 a[n_] := Numerator[DivisorSigma[-1, 2*n]]; Array[a, 100] (* _Amiram Eldar_, Dec 14 2024 *)
%o A378995 (PARI) A378995(n) = numerator(sigma(2*n)/(2*n));
%Y A378995 Even bisection of A017665.
%Y A378995 Topmost row of array A341605.
%Y A378995 Cf. A062731, A245058, A378994, A378996 (denominators).
%Y A378995 Cf. also A341525.
%K A378995 nonn,frac,easy
%O A378995 1,1
%A A378995 _Antti Karttunen_, Dec 13 2024