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 A133556 #10 May 10 2017 21:29:28 %S A133556 1,9,187,11881,3720993,4652194849,21048197450115,362982575751004609, %T A133556 24187438805159042241345,6154694340999818634869088969, %U A133556 5974124007380479364088559506443355 %N A133556 Number of n X n binary matrices with every 1 diagonally or antidiagonally adjacent to some 0. %C A133556 Number of dominating sets in the direct product of the graphs P_n and P_n. - _Andrew Howroyd_, May 10 2017 %H A133556 Wikipedia, <a href="https://en.wikipedia.org/wiki/Tensor_product_of_graphs">Tensor product of graphs</a>, <a href="https://en.wikipedia.org/wiki/Dominating_set">Dominating set</a> %Y A133556 Cf. A133515, A133791. %K A133556 nonn %O A133556 1,2 %A A133556 _R. H. Hardin_, Dec 25 2007