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 A061322 #15 Apr 17 2024 07:54:00
%S A061322 2,6,15,40,140,924,24640,12415040,2408343949440,
%T A061322 71606426901226335015040,51274803735606705472274088614112357905277056,
%U A061322 21728144612603201307908899563300049012978385050783094682272184269369267136230071558272
%N A061322 a(n) = a(n-1) * (1 + a(n-1)/n^2) with a(0) = 2.
%C A061322 Only first 42 terms are integers (see A003504).
%H A061322 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/GoebelsSequence.html">Goebel's Sequence</a>.
%F A061322 a(n) = a(n-1) + A003504(n+1)^2, a(n-1) = n * A003504(n+1). a(n) = A061314(2, n).
%e A061322 a(2) = 6 * (1 + 6/2^2) = 15.
%t A061322 Block[{n = 0}, NestList[#*(1 + #/++n^2) &, 2, 11]] (* _Paolo Xausa_, Apr 17 2024 *)
%o A061322 (PARI) {a(n) = local(x); if( n<1, 2 * (n==0), (x = a(n-1)) + (x/n)^2)} /* _Michael Somos_, Apr 02 2006 */
%K A061322 nonn
%O A061322 0,1
%A A061322 _Henry Bottomley_, Apr 24 2001