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 A069972 #13 Mar 02 2023 16:53:23
%S A069972 1,1,3,1,1,6,1,1,3,5,1,6,1,1,8,1,1,6,1,5,9,1,1,6,1,1,3,8,1,15,1,1,3,1,
%T A069972 1,14,1,1,3,5,1,12,1,1,17,1,1,6,1,5,3,1,1,6,11,8,3,1,1,15,1,1,9,1,1,
%U A069972 17,1,1,3,5,1,14,1,1,8,1,1,18,1,5,3,1,1,19,1,1,3,1,1,24,14,1,3,1,1,6,1,1
%N A069972 a(n) = Sum_{d|2*n,d+1|2*n} d.
%H A069972 Antti Karttunen, <a href="/A069972/b069972.txt">Table of n, a(n) for n = 1..20000</a>
%F A069972 G.f.: (conjectured) Sum_{n>=1} n*x^(n*(n+1)/2)/(1-x^(n*(n+1)/2)). - _Joerg Arndt_, Jan 30 2011
%o A069972 (PARI) A069972(n) = { n = 2*n; sumdiv(n,d,if(!(n%(1+d)), d, 0)); }; \\ _Antti Karttunen_, Mar 02 2023
%Y A069972 Cf. A007862.
%K A069972 easy,nonn
%O A069972 1,3
%A A069972 _Vladeta Jovovic_, Apr 29 2002