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 A123354 #12 Feb 24 2025 08:52:44 %S A123354 1,1,1,1,3,1,1,6,9,1,1,10,40,27,1,1,15,125,272,81,1,1,21,315,1625, %T A123354 1856,243,1,1,28,686,6993,21250,12672,729,1,1,36,1344,24010,156411, %U A123354 278125,86528,2187,1,1,45,2430,69888,847553,3501873,3640625,590848,6561,1 %N A123354 Triangle read by rows, giving Kekulé numbers for certain benzenoids (see the Cyvin-Gutman book for details). %D A123354 S. J. Cyvin and I. Gutman, Kekulé structures in benzenoid hydrocarbons, Lecture Notes in Chemistry, No. 46, Springer, New York, 1988 (see p. 210). %e A123354 Triangle begins: %e A123354 1 %e A123354 1 1 %e A123354 1 3 1 %e A123354 1 6 9 1 %e A123354 1 10 40 27 1 %e A123354 1 15 125 272 81 1 %e A123354 1 21 315 1625 1856 243 1 %e A123354 1 28 686 6993 21250 12672 729 1 %e A123354 1 36 1344 24010 156411 278125 86528 2187 1 %e A123354 1 45 2430 69888 847553 3501873 3640625 590848 6561 1 %e A123354 1 55 4125 179334 3667968 29950074 78413427 47656250 4034560 19683 1 %Y A123354 Diagonals give A000244, A123357, A123358. %K A123354 nonn,tabl %O A123354 0,5 %A A123354 _N. J. A. Sloane_, Oct 14 2006