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 A224736 #8 Mar 27 2025 04:23:58 %S A224736 1,16,776,64384,7151460,947788608,141137282720,22814994697728, %T A224736 3918995299504938,705339416079749024,131725296229995045840, %U A224736 25348575698532710671104,5000341179482293108254824,1007144334380887781805059200,206487157000689985136888031296 %N A224736 G.f.: exp( Sum_{n>=1} binomial(2*n,n)^4 * x^n/n ). %F A224736 Logarithmic derivative yields A186420. %e A224736 G.f.: A(x) = 1 + 16*x + 776*x^2 + 64384*x^3 + 7151460*x^4 + 947788608*x^5 +... %e A224736 where %e A224736 log(A(x)) = 2^4*x + 6^4*x^2/2 + 20^4*x^3/3 + 70^4*x^4/4 + 252^4*x^5/5 + 924^4*x^6/6 + 3432^4*x^7/7 + 12870^4*x^8/8 +...+ A000984(n)^4*x^n/n +... %t A224736 CoefficientList[Series[Exp[16*x*HypergeometricPFQ[{1, 1, 3/2, 3/2, 3/2, 3/2}, {2, 2, 2, 2, 2}, 256*x]], {x, 0, 20}], x] (* _Vaclav Kotesovec_, Mar 27 2025 *) %o A224736 (PARI) {a(n)=polcoeff(exp(sum(k=1,n,binomial(2*k,k)^4*x^k/k)+x*O(x^n)),n)} %o A224736 for(n=0,20,print1(a(n),", ")) %Y A224736 Cf. A224732, A224734, A224735, A186420, A000984. %K A224736 nonn %O A224736 0,2 %A A224736 _Paul D. Hanna_, Apr 16 2013