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 A092123 #3 Apr 30 2014 01:30:31
%S A092123 1,1,2,10,302,391232,912140731560,6870302396056798235043564,
%T A092123 552249828443015013351729477795257932661645918815144
%N A092123 Largest coefficient in expansion of P(0)=x, P(n+1)=P(n)*[1+P(n)].
%C A092123 It would be nice to have a formula for the 2^(n-1)th coefficient.
%C A092123 The exponent of x in P(n) with a(n) as coefficient is {1,1,2,5,9,19,37,74,147,294,587,1175,...}.
%o A092123 (PARI) P(n)=if(n<1,x,P(n-1)*(P(n-1)+1))
%o A092123 (PARI) a(n)=vecmax(Vec(P(n)))
%Y A092123 Cf. A016131.
%K A092123 nonn
%O A092123 0,3
%A A092123 _Ralf Stephan_, Apr 02 2004