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 A206157 #9 Nov 09 2024 17:28:19
%S A206157 1,2,7,102,6261,2423430,6686021554,61335432894584,2941073857435300366,
%T A206157 1190520035262419577871332,1696475310227140760623646031573,
%U A206157 9980324833243234634513255755001535870,565171444566758371735408026461987217216896790
%N A206157 G.f.: exp( Sum_{n>=1} A206158(n)*x^n/n ), where A206158(n) = Sum_{k=0..n} binomial(n,k)^(2*k+1).
%C A206157 Logarithmic derivative yields A206158.
%e A206157 G.f.: A(x) = 1 + 2*x + 7*x^2 + 102*x^3 + 6261*x^4 + 2423430*x^5 +...
%e A206157 where the logarithm of the g.f. begins:
%e A206157 log(A(x)) = 2*x + 10*x^2/2 + 272*x^3/3 + 24226*x^4/4 + 12053252*x^5/5 + 40086916024*x^6/6 +...+ A206158(n)*x^n/n +...
%o A206157 (PARI) {a(n)=polcoeff(exp(sum(m=1,n+1,x^m/m*sum(k=0,m,binomial(m,k)^(2*k+1))+x*O(x^n))),n)}
%o A206157 for(n=0,16,print1(a(n),", "))
%Y A206157 Cf. A206158 (log), A184730, A206153, A206155, A206151.
%K A206157 nonn
%O A206157 0,2
%A A206157 _Paul D. Hanna_, Feb 04 2012