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 A194497 #8 Oct 27 2019 22:12:18 %S A194497 0,0,0,0,0,0,0,0,0,10,1210,27198,322782,2564988,15372702,74615814, %T A194497 306900410,1105651074,3569169990,10512880400,28628691842,72880455042, %U A194497 174895586328,398556484840,867314768878,1811576604968,3646385889888 %N A194497 Number of ways to arrange 7 nonattacking queens on the lower triangle of an n X n board. %C A194497 Column 7 of A194498. %H A194497 R. H. Hardin, <a href="/A194497/b194497.txt">Table of n, a(n) for n = 1..28</a> %e A194497 Some solutions for 10 X 10: %e A194497 0 0 0 %e A194497 0 0 0 0 0 0 %e A194497 0 0 0 0 0 0 0 0 0 %e A194497 0 1 0 0 0 1 0 0 0 0 0 1 %e A194497 0 0 0 1 0 0 0 0 1 0 1 0 0 0 0 %e A194497 1 0 0 0 0 0 0 0 0 0 0 1 0 0 1 0 0 0 %e A194497 0 0 0 0 0 0 1 1 0 0 0 0 0 0 0 0 0 0 0 1 0 %e A194497 0 0 0 0 1 0 0 0 0 0 1 0 0 0 0 0 0 1 0 0 0 0 0 0 %e A194497 0 0 1 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 1 0 0 %e A194497 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 0 %K A194497 nonn %O A194497 1,10 %A A194497 _R. H. Hardin_, Aug 26 2011