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 A220836 #17 Aug 21 2020 13:09:52 %S A220836 1,1,2,1,4,4,1,6,13,9,1,8,26,38,20,1,10,43,96,106,45,1,12,64,190,321, %T A220836 284,101,1,14,89,328,742,1006,742,227,1,16,118,518,1460,2660,3006, %U A220836 1900,510 %N A220836 Triangle read by rows giving coefficients of Zhang-Zhang polynomial for benzenoidal system S(n). %H A220836 C.-P. Chou and H. A. Witek, <a href="http://match.pmf.kg.ac.rs/electronic_versions/Match68/n1/match68n1_3-30.pdf">An Algorithm and FORTRAN Program for Automatic Computation of the Zhang-Zhang Polynomial of Benzenoids</a>, MATCH: Commun. Math. Comput. Chem, 68 (2012) 3-30. %F A220836 Chou and Witek give a g.f. %e A220836 Triangle begins: %e A220836 1 %e A220836 1 2 %e A220836 1 4 4 %e A220836 1 6 13 9 %e A220836 1 8 26 38 20 %e A220836 1 10 43 96 106 45 %e A220836 1 12 64 190 321 284 101 %e A220836 1 14 89 328 742 1006 742 227 %e A220836 1 16 118 518 1460 2660 3006 1900 510 %e A220836 ... %Y A220836 Right hand diagonal is A052534. %K A220836 nonn,tabl %O A220836 1,3 %A A220836 _N. J. A. Sloane_, Dec 23 2012