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 A100431 #19 Apr 10 2023 14:05:56
%S A100431 8,80,336,960,2200,4368,7840,13056,20520,30800,44528,62400,85176,
%T A100431 113680,148800,191488,242760,303696,375440,459200,556248,667920,
%U A100431 795616,940800,1105000,1289808,1496880,1727936,1984760,2269200,2583168,2928640,3307656,3722320
%N A100431 Bisection of A002417.
%H A100431 G. C. Greubel, <a href="/A100431/b100431.txt">Table of n, a(n) for n = 0..1000</a>
%H A100431 <a href="/index/Rec#order_05">Index entries for linear recurrences with constant coefficients</a>, signature (5,-10,10,-5,1).
%F A100431 a(n) = (4/3)*(2*n^4 + 11*n^3 + 22*n^2 + 19*n + 6). - _Ralf Stephan_, May 15 2007
%F A100431 G.f.: 8*(1 + 5*x + 2*x^2)/(1 - x)^5. - _Ilya Gutkovskiy_, Feb 24 2017
%F A100431 From _G. C. Greubel_, Apr 09 2023: (Start)
%F A100431 a(n) = (8/3)*binomial(n+2, 2)*binomial(2*n+3, 2).
%F A100431 a(n) = (8/3)*A000217(n+1)*A014105(n+1).
%F A100431 a(n) = 8*A108678(n).
%F A100431 a(n) = 4*A098077(n+1).
%F A100431 E.g.f.: (4/3)*(6 + 54*x + 69*x^2 + 23*x^3 + 2*x^4)*exp(x). (End)
%t A100431 Table[4*(n+1)^2(n+2)(2n+3)/3, {n,0,60}] (* _Vladimir Joseph Stephan Orlovsky_, Jul 07 2011 *)
%o A100431 (Magma) [4*(n+1)^2*(n+2)*(2*n+3)/3: n in [0..60]]; // _G. C. Greubel_, Apr 09 2023
%o A100431 (SageMath) [4*(n+1)^2*(n+2)*(2*n+3)/3 for n in range(61)] # _G. C. Greubel_, Apr 09 2023
%Y A100431 Cf. A000217, A002417, A014105, A098077, A108678.
%K A100431 nonn,easy
%O A100431 0,1
%A A100431 _N. J. A. Sloane_, Nov 20 2004
%E A100431 More terms from _Hugo Pfoertner_, Nov 26 2004