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 A384691 #10 Jun 07 2025 08:21:50 %S A384691 1,1,7,112,2989,115136,5899159,381657928,30082660633,2814548348224, %T A384691 306467497027531,38242238970083336,5401465336487870533, %U A384691 854848596955885610560,150317821473136130378335,29159232358630752927016456,6201999009581132843649181489,1438725999127826885623788697472 %N A384691 E.g.f. A(x) satisfies A(x) = exp( x*A(x) * A(x*A(x))^2 ). %F A384691 See A384692. %t A384691 terms = 18; A[_] = 0; Do[A[x_] = Exp[x*A[x]*A[x*A[x]]^2] + O[x]^terms // Normal, terms]; Range[0,terms-1]!CoefficientList[A[x], x] (* _Stefano Spezia_, Jun 07 2025 *) %o A384691 (PARI) a(n, k=1) = if(k==0, 0^n, k*sum(j=0, n, (n+k)^(j-1)*binomial(n, j)*a(n-j, 2*j))); %Y A384691 Column k=1 of A384692. %K A384691 nonn %O A384691 0,3 %A A384691 _Seiichi Manyama_, Jun 07 2025