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 A008033 #22 Dec 17 2022 12:43:03
%S A008033 1,4,10,20,35,54,76,104,136,171,211,254,302,355,411,471,536,606,679,
%T A008033 756,837,922,1013,1107,1204,1307,1414,1525,1640,1758,1881,2009,2141,
%U A008033 2276,2416,2561,2709,2862,3018,3178,3344,3513,3686,3864,4046,4232,4422,4616
%N A008033 Coordination sequence T2 for Zeolite Code APC.
%D A008033 W. M. Meier, D. H. Olson and Ch. Baerlocher, Atlas of Zeolite Structure Types, 4th Ed., Elsevier, 1996
%H A008033 R. W. Grosse-Kunstleve, <a href="/A008033/b008033.txt">Table of n, a(n) for n = 0..1000</a>
%H A008033 R. W. Grosse-Kunstleve, <a href="/A005897/a005897.html">Coordination Sequences and Encyclopedia of Integer Sequences</a>
%H A008033 R. W. Grosse-Kunstleve, G. O. Brunner, and N. J. A. Sloane, <a href="http://neilsloane.com/doc/ac96cs/">Algebraic Description of Coordination Sequences and Exact Topological Densities for Zeolites</a>, Acta Cryst., A52 (1996), pp. 879-889.
%H A008033 Sean A. Irvine, <a href="/A008000/a008000_1.pdf">Generating Functions for Coordination Sequences of Zeolites, after Grosse-Kunstleve, Brunner, and Sloane</a>
%H A008033 International Zeolite Association, <a href="http://www.iza-structure.org/databases/">Database of Zeolite Structures</a>
%F A008033 G.f.: (1 + x)*(1 + 2*x + 4*x^2 + 6*x^3 + 9*x^4 + 9*x^5 + 10*x^6 + 12*x^7 + 10*x^8 + 9*x^9 + 9*x^10 + 6*x^11 + 4*x^12 + 2*x^13 + x^14) / ((1 - x)^3*(1 + x + x^2)*(1 + x + x^2 + x^3 + x^4)*(1 + x^3 + x^6)). - _Colin Barker_, Dec 20 2015
%F A008033 G.f.: (1 + 3*x + 6*x^2 + 10*x^3 + 15*x^4 + 18*x^5 + 19*x^6 + 22*x^7 + 22*x^8 + 19*x^9 + 18*x^10 + 15*x^11 + 10*x^12 + 6*x^13 + 3*x^14 + x^15) / (1 - x) / (1 - x^5) / (1 - x^9). - _Sean A. Irvine_, Mar 13 2018
%F A008033 a(n) ~ 94*n^2/45. - _Stefano Spezia_, Dec 17 2022
%t A008033 CoefficientList[Series[(1 + 3*x + 6*x^2 + 10*x^3 + 15*x^4 + 18*x^5 + 19*x^6 + 22*x^7 + 22*x^8 + 19*x^9 + 18*x^10 + 15*x^11 + 10*x^12 + 6*x^13 + 3*x^14 + x^15)/(1-x)/(1-x^5)/(1-x^9),{x,0,47}],x] (* _Stefano Spezia_, Dec 17 2022 *)
%K A008033 nonn,easy
%O A008033 0,2
%A A008033 _Ralf W. Grosse-Kunstleve_