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 A162631 #8 Sep 08 2022 08:45:46
%S A162631 1,13,91,454,1807,6097,18108,48555,119691,274911,594438,1219920,
%T A162631 2391662,4503266,8179652,14385775,24574822,40886248,66405664,
%U A162631 105500290,164245393,250958800,376862161,556889086,810661540,1163656897
%N A162631 G.f. is the polynomial (1-x^3) * (1-x^6) * (1-x^9) * (1-x^12) * (1-x^15) * (1-x^18) * (1-x^21) * (1-x^24) * (1-x^27) * (1-x^30) * (1-x^33) * (1-x^36) * (1-x^39) / (1-x)^13.
%C A162631 This is a row of the triangle in A162499. Only finitely many terms are nonzero.
%H A162631 G. C. Greubel, <a href="/A162631/b162631.txt">Table of n, a(n) for n = 0..260</a>
%t A162631 CoefficientList[Series[(Times@@(1-x^(3*Range[13])))/(1-x)^13,{x,0,30}],x] (* _Harvey P. Dale_, May 09 2016 *)
%o A162631 (PARI) x='x+O('x^50); Vec((1-x^3)*(1-x^6)*(1-x^9)*(1-x^12)*(1-x^15)*(1-x^18)*(1-x^21)*(1-x^24)*(1-x^27)*(1-x^30)*(1-x^33)*(1-x^36)*(1-x^39)/(1-x)^13) \\ _G. C. Greubel_, Jul 06 2018
%o A162631 (Magma) m:=50; R<x>:=PowerSeriesRing(Integers(), m); Coefficients(R!((1-x^3)*(1-x^6)*(1-x^9)*(1-x^12)*(1-x^15)*(1-x^18)*(1-x^21)*(1-x^24)*(1-x^27)*(1-x^30)*(1-x^33)*(1-x^36)*(1-x^39)/(1-x)^13)); // _G. C. Greubel_, Jul 06 2018
%K A162631 nonn
%O A162631 0,2
%A A162631 _N. J. A. Sloane_, Dec 02 2009