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 A203507 #11 Dec 17 2024 17:05:52
%S A203507 1,3,15,82,504,3198,21592,147570,1045221,7464052,54549804,400487997,
%T A203507 2990765270,22396990002,169881957174,1291189065086,9910770901971,
%U A203507 76178174174205,590312326353680,4578346159792815,35745960436892046,279290158338688617
%N A203507 G.f.: Product_{n>=0} 1/(1-a(n)*x^(n+1))^3 = Sum_{n>=0} a(n)*x^n.
%e A203507 G.f.: A(x) = 1 + 3*x + 15*x^2 + 82*x^3 + 504*x^4 + 3198*x^5 + 21592*x^6 +...
%e A203507 where
%e A203507 A(x) = 1/((1-x)*(1-3*x^2)*(1-15*x^3)*(1-82*x^4)*(1-504*x^5)*...)^3.
%e A203507 Related expansion:
%e A203507 A(x)^(1/3) = 1 + x + 4*x^2 + 19*x^3 + 110*x^4 + 659*x^5 + 4355*x^6 +...
%o A203507 (PARI) {a(n) = polcoeff(prod(k=0, n-1, 1/(1-a(k)*x^(k+1)+x*O(x^n)))^3, n)}
%Y A203507 Cf. A093637, A093638.
%K A203507 nonn
%O A203507 0,2
%A A203507 _Paul D. Hanna_, Jan 02 2012