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 A180756 #5 Jul 22 2025 08:28:40 %S A180756 0,8,14,207,1874,20205,205020,2141384,22238670,232041425,2420128480, %T A180756 25258683242,263607333975,2751296309311,28715052573470, %U A180756 299699771800630,3127972672911502,32646796609958085,340736340129916559 %N A180756 Half the number of nX7 binary arrays with each element equal to at least two neighbors. %C A180756 Column 7 of A180760 %H A180756 R. H. Hardin, <a href="/A180756/b180756.txt">Table of n, a(n) for n=1..99</a> %K A180756 nonn %O A180756 1,2 %A A180756 _R. H. Hardin_ Sep 20 2010