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 A240648 #6 Jul 23 2025 11:04:53 %S A240648 8,21,149,526,4343,29481,227270,1748201,14230080,116070258,970291863, %T A240648 8167942037,69515482202,595126853497,5123195518181,44273991533826, %U A240648 383829145390407,3335510350046976,29039638981754848,253185283934243073 %N A240648 Number of nX7 0..1 arrays with no element equal to the same number of vertical neighbors as horizontal neighbors, with new values 0..1 introduced in row major order. %C A240648 Column 7 of A240649 %H A240648 R. H. Hardin, <a href="/A240648/b240648.txt">Table of n, a(n) for n = 1..169</a> %e A240648 Some solutions for n=4 %e A240648 ..0..0..0..0..0..1..0....0..0..0..0..0..1..0....0..1..0..1..0..1..0 %e A240648 ..1..1..1..1..1..1..0....1..0..1..1..1..1..0....0..1..0..1..0..1..0 %e A240648 ..0..0..1..0..0..1..0....1..0..0..0..1..1..0....1..1..1..1..0..1..0 %e A240648 ..1..1..1..1..1..1..1....1..0..1..1..1..1..1....0..0..0..1..0..1..0 %K A240648 nonn %O A240648 1,1 %A A240648 _R. H. Hardin_, Apr 09 2014