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 A239900 #17 Sep 08 2022 08:46:07
%S A239900 2,5,11,111,12211,149096311,22229709804712411,
%T A239900 494159998001727075769152612720511
%N A239900 a(0)=2, a(1)=5; thereafter a(n) = product of all preceding terms, plus 1.
%H A239900 Robert Munafo, <a href="http://mrob.com/pub/math/nu-sequences.html#table">Some integer sequences</a>
%H A239900 Robert Munafo, <a href="http://mrob.com/pub/seq/coprime.html">Mutually coprime sequences</a>
%t A239900 nxt[{t_,a_}]:=Module[{k=t+1},{t k,k}]; Join[{2},NestList[nxt,{10,5},7][[All,2]]] (* _Harvey P. Dale_, Oct 25 2020 *)
%o A239900 (Magma) I:=[2,5,11]; [n le 3 select I[n] else Self(n-1)*(Self(n-1)-1)+1: n in [1..10]]; // _Vincenzo Librandi_, May 22 2014
%Y A239900 A variant of A144784. Cf. A239900.
%K A239900 nonn
%O A239900 0,1
%A A239900 _N. J. A. Sloane_, Apr 05 2014
%E A239900 a(6) corrected by _Harvey P. Dale_, Oct 25 2020