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 A172816 #8 Apr 18 2020 22:24:28 %S A172816 1,19,415,10147,261331,7100821,200148649,5796870115,171475190227, %T A172816 5158851352489,157366288875709,4855940642591941,151309409779981285, %U A172816 4754260599949620163,150466404665460290335,4792275283921293214435 %N A172816 Number of n X 4 0..4 arrays with row sums 4 and column sums n. %H A172816 R. H. Hardin, <a href="/A172816/b172816.txt">Table of n, a(n) for n=1..99</a> %Y A172816 Column k=4 of A333901. %K A172816 nonn %O A172816 1,2 %A A172816 _R. H. Hardin_, Feb 06 2010