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 A240517 #6 Jul 23 2025 11:02:14 %S A240517 13,42,196,1080,6205,37624,231665,1440880,9082172,57688194,368247913, %T A240517 2360899744,15185317117,97900171826,632299574804,4089240246144, %U A240517 26472263944273,171499150683304,1111664911286921,7208828328348392 %N A240517 Number of nX6 0..1 arrays with no element equal to exactly two horizontal and vertical neighbors, with new values 0..1 introduced in row major order. %C A240517 Column 6 of A240519 %H A240517 R. H. Hardin, <a href="/A240517/b240517.txt">Table of n, a(n) for n = 1..210</a> %e A240517 Some solutions for n=4 %e A240517 ..0..1..0..1..0..1....0..0..1..0..1..0....0..1..0..0..1..0....0..1..0..0..0..1 %e A240517 ..1..0..1..0..0..0....1..1..1..0..1..1....0..1..1..1..1..1....1..0..1..0..1..0 %e A240517 ..1..1..0..1..1..1....0..1..1..1..1..0....1..1..1..1..1..0....0..1..1..1..0..1 %e A240517 ..1..0..1..0..1..0....1..1..1..1..1..1....0..0..1..0..1..0....1..0..1..0..0..0 %K A240517 nonn %O A240517 1,1 %A A240517 _R. H. Hardin_, Apr 06 2014