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 A192441 #18 Sep 08 2022 08:45:57
%S A192441 1,0,2,3,6,30,35,210,350,1344,3402,9240,29139,72072,231660,603603,
%T A192441 1814670,5095376,14507324,42401502,118974466,349305120,990073812,
%U A192441 2877816304,8272748675,23852438880,69116072950,198980348385,577566713520,1667118322590,4834810467135
%N A192441 Coefficient of x^(2*n) in the expansion of (1 + x^3 + x^4)^n.
%H A192441 Vincenzo Librandi, <a href="/A192441/b192441.txt">Table of n, a(n) for n = 0..200</a>
%F A192441 a(n) = Sum_{k=ceiling(n/2)..floor(2*n/3)} binomial(n,k)*binomial(k,2*n-3*k). - _R. J. Mathar_, Jul 01 2011
%o A192441 (PARI) a(n)=polcoeff((1+x^3+x^4)^n,2*n);
%o A192441 (Maxima) makelist((coeff(expand((1+x^3+x^4)^n), x, 2*n)), n, 0, 30); /* _Bruno Berselli_, Jul 01 2011 */
%o A192441 (Magma) P<x>:=PolynomialRing(Integers()); [ Coefficients((1+x^3+x^4)^n)[ 2*n+1 ]: n in [0..30] ]; // _Bruno Berselli_, Jul 01 2011
%Y A192441 Cf. A002426, A192440.
%K A192441 nonn
%O A192441 0,3
%A A192441 _Joerg Arndt_, Jul 01 2011