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 A172642 #6 Jul 22 2025 07:35:27 %S A172642 1,19,175,2371,32611,481381,7343449,115321795,1849858771,30189264889, %T A172642 499616140189,8365213132981,141444270208645,2411829493241299, %U A172642 41425627536496495,716068213864217155,12447291755448613315 %N A172642 Number of n X 4 0..2 arrays with row sums 4 and column sums n. %H A172642 R. H. Hardin, <a href="/A172642/b172642.txt">Table of n, a(n) for n=1..99</a> %K A172642 nonn %O A172642 1,2 %A A172642 _R. H. Hardin_ Feb 06 2010