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 A120591 #3 Mar 30 2012 18:36:58
%S A120591 1,3,12,76,600,5304,50232,498360,5112756,53796820,577370508,
%T A120591 6295961100,69557631936,776913430272,8758443555360,99527014659360,
%U A120591 1138832618425272,13110313153525272,151738042878341400,1764609260161776600
%N A120591 Self-convolution cube of A120590, such that a(n) = 4*A120590(n) for n>=2.
%e A120591 A(x) = 1 + 3*x + 12*x^2 + 76*x^3 + 600*x^4 + 5304*x^5 + 50232*x^6 +...
%e A120591 A(x)^(1/3) = 1 + x + 3*x^2 + 19*x^3 + 150*x^4 + 1326*x^5 + 12558*x^6 +...
%o A120591 (PARI) {a(n)=local(A=1+x+3*x^2+x*O(x^n));for(i=0,n,A=A-4*A+3+x+A^3);polcoeff(A^3,n)}
%Y A120591 Cf. A120590 (A(x)^(1/3)); A120588, A120592 - A120607.
%K A120591 nonn
%O A120591 0,2
%A A120591 _Paul D. Hanna_, Jun 16 2006