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 A211897 #6 Apr 25 2012 00:42:27
%S A211897 1,1,13,127,21079,5748277,12575820727,76137769800001,
%T A211897 2378969789430032869,263966921383940194614823,
%U A211897 128008718415112846211347561597,240383035701447602719960666753525867,1863847508172945183054545696402414919578641
%N A211897 G.f.: exp( Sum_{n>=1} (2^n + (-1)^n)^n * x^n/n ).
%F A211897 a(n) == 1 (mod 6).
%e A211897 G.f.: A(x) = 1 + x + 13*x^2 + 127*x^3 + 21079*x^4 + 5748277*x^5 +...
%e A211897 such that
%e A211897 log(A(x)) = x + 5^2*x^2 + 7^3*x^3 + 17^4*x^4 + 31^5*x^5 + 65^6*x^6 + 127^7*x^7 +...+ (2^n + (-1)^n)^n*x^n/n +...
%o A211897 (PARI) {a(n)=polcoeff(exp(sum(k=1, n, (2^k+(-1)^k)^k*x^k/k)+x*O(x^n)), n)}
%o A211897 for(n=0, 20, print1(a(n), ", "))
%Y A211897 Cf. A211898, A155200.
%K A211897 nonn
%O A211897 0,3
%A A211897 _Paul D. Hanna_, Apr 25 2012