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 A180758 #5 Jul 22 2025 08:28:54 %S A180758 0,21,67,2059,41755,986376,22238670,514990479,11843513563, %T A180758 273193577866,6295815062637,145178091690740,3347707869286493, %U A180758 77204310077778551,1780484848971706031,41062118413701907548,946988189894419322573 %N A180758 Half the number of nX9 binary arrays with each element equal to at least two neighbors. %C A180758 Column 9 of A180760 %H A180758 R. H. Hardin, <a href="/A180758/b180758.txt">Table of n, a(n) for n=1..99</a> %K A180758 nonn %O A180758 1,2 %A A180758 _R. H. Hardin_ Sep 20 2010