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 A138912 #4 Jul 27 2025 18:56:05
%S A138912 1,1,2,9,28,145,726,4249,27000,186561,1387450,11034001,93295236,
%T A138912 834720913,7870851366,77943848025,808159323376,8749874083585,
%U A138912 98687599614450,1157060036429857,14075106913366140,177337182574590801,2310567819180310558,31087556340427928617
%N A138912 Inverse binomial transform of A138911.
%C A138912 The n-th term of the n-th inverse binomial transform of A138911 is 1 for n>=0.
%F A138912 O.g.f. satisfies: [x^n] A( x/(1+(n-1)*x) )/(1+(n-1)*x) = 1 for n>=0.
%F A138912 E.g.f. satisfies: [x^n] A(x)*exp(-(n-1)*x) = 1/n! for n>=0.
%o A138912 (PARI) {a(n)=local(A=[1]);for(k=1,n,A=concat(A,0); A[k+1]=1-polcoeff(subst(Ser(A),x,x/(1+(k-1)*x+x*O(x^k)))/(1+(k-1)*x),k));A[n+1]}
%Y A138912 Cf. A138911 (binomial transform).
%K A138912 nonn
%O A138912 0,3
%A A138912 _Paul D. Hanna_, Apr 05 2008