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 A263677 #15 Dec 12 2015 04:58:53 %S A263677 1,1,3,1,3,1,28,15,11,0,6,3,30,16,0,0,3,3 %N A263677 Irregular table read by rows, n >= 1, k >= 0: T(n,k) is the number of binary symmetric n X n matrices with k holes that are squares, where the axes of symmetry are horizontal and vertical. %C A263677 Inspired by A258643 but the axes of symmetry are the same as in A262742. The mirror patterns and nonsquare holes are excluded. %H A263677 Kival Ngaokrajang, <a href="/A263677/a263677.pdf">Illustration of initial terms</a> %e A263677 Irregular table begins: %e A263677 n\k 0 1 2 3 4 5 ... %e A263677 1 1 %e A263677 2 1 %e A263677 3 3 1 %e A263677 4 3 1 %e A263677 5 28 15 11 0 6 3 %e A263677 6 30 16 0 0 3 3 %e A263677 ... %Y A263677 Cf. A258643, A262742. %K A263677 nonn,tabf,more %O A263677 1,3 %A A263677 _Kival Ngaokrajang_, Oct 23 2015