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 A205773 #6 Mar 30 2012 18:37:34
%S A205773 1,3,21,156,1335,12153,116778,1160715,11848530,123420648,1306709841,
%T A205773 14019657771,152092615971,1665531792021,18386262679557,
%U A205773 204393214435791,2286101345820933,25708109998131381,290490321604346535,3296566844230833750,37555644504960139647
%N A205773 G.f. satisfies: A(x) = 1/Product_{n>=1} (1 - 3*x^n*A(x^n)).
%e A205773 G.f.: A(x) = 1 + 3*x + 21*x^2 + 156*x^3 + 1335*x^4 + 12153*x^5 +...
%e A205773 where
%e A205773 A(x) = 1/((1 - 3*x*A(x)) * (1 - 3*x^2*A(x^2)) * (1 - 3*x^3*A(x^3)) *...).
%o A205773 (PARI) {a(n)=local(A=1+x); for(i=1, n, A=1/prod(k=1, n, (1-3*x^k*subst(A, x, x^k+x*O(x^n))))); polcoeff(A, n)}
%Y A205773 Cf. A050383, A196192, A205772.
%K A205773 nonn
%O A205773 0,2
%A A205773 _Paul D. Hanna_, Jan 31 2012