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 A219442 #6 Jul 23 2025 00:27:53 %S A219442 1,47,329,1750,10157,57249,326938,1871991,10717083,61406130,351621409, %T A219442 2013957691,11534261710,66064401075,378390334671,2167284760374, %U A219442 12413363760441,71098932771545,407227101232548,2332439882554127 %N A219442 Unmatched value maps: number of 4Xn binary arrays indicating the locations of corresponding elements not equal to any horizontal, diagonal or antidiagonal neighbor in a random 0..1 4Xn array. %C A219442 Row 4 of A219441 %H A219442 R. H. Hardin, <a href="/A219442/b219442.txt">Table of n, a(n) for n = 1..30</a> %e A219442 Some solutions for n=3 %e A219442 ..0..0..1....1..0..0....1..0..1....0..0..0....1..0..0....1..1..1....0..0..0 %e A219442 ..1..0..1....0..0..1....0..0..0....0..0..1....0..0..0....1..0..1....1..0..1 %e A219442 ..0..1..0....0..0..1....0..0..1....0..0..1....0..0..1....0..0..0....1..1..1 %e A219442 ..0..0..0....1..0..1....0..0..0....0..0..0....0..0..1....1..0..0....1..1..1 %K A219442 nonn %O A219442 1,2 %A A219442 _R. H. Hardin_ Nov 20 2012