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 A112125 #6 Mar 13 2015 23:48:15
%S A112125 1,1,-10,160,-3061,63775,-1381434,30233546,-654989371,13821523157,
%T A112125 -280493565375,5432981693533,-100769609590332,1833421110751790,
%U A112125 -34286913831217395,678578947805323394,-13377225136748683778,221000164094797572734,-2119677884300620846621
%N A112125 G.f. A(x) satisfies A(A(A(..(A(x))..))) = B(x) (12th self-COMPOSE of A) such that the coefficients of B(x) consist only of numbers {1,2,3,..,12}, with B(0) = 0.
%e A112125 A(x) = x + x^2 - 10*x^3 + 160*x^4 - 3061*x^5 + 63775*x^6 +...
%e A112125 where A(A(A(A(A(A(A(A(A(A(A(A(x)))))))))))) =
%e A112125 x + 12*x^2 + 12*x^3 + 6*x^4 + 8*x^5 + 8*x^6 + 12*x^7 + 2*x^8 +...
%e A112125 is the g.f. of A112124.
%o A112125 (PARI) {a(n,m=12)=local(F=x+x^2+x*O(x^n),G);if(n<1,0, for(k=3,n, G=F+x*O(x^k);for(i=1,m-1,G=subst(F,x,G)); F=F-((polcoeff(G,k)-1)\m)*x^k); return(polcoeff(F,n,x)))}
%Y A112125 Cf. A112124, A112104-A112123, A112126, A112127.
%K A112125 sign
%O A112125 1,3
%A A112125 _Paul D. Hanna_, Aug 27 2005