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 A219140 #6 Jul 23 2025 00:16:03 %S A219140 21,225,4033,59127,872437,12867295,191707377,2851740545,42351530487, %T A219140 628917557052,9343657589877,138832484811480,2062679454951201, %U A219140 30644671161036036,455284849342096283,6764205083943142280 %N A219140 Unchanging value maps: number of nX6 binary arrays indicating the locations of corresponding elements unequal to no horizontal, diagonal or antidiagonal neighbor in a random 0..2 nX6 array. %C A219140 Column 6 of A219142 %H A219140 R. H. Hardin, <a href="/A219140/b219140.txt">Table of n, a(n) for n = 1..31</a> %e A219140 Some solutions for n=3 %e A219140 ..0..0..0..0..1..0....1..1..1..0..0..1....1..1..0..0..0..0....1..0..0..0..0..0 %e A219140 ..0..0..1..0..0..0....1..1..1..0..0..0....1..0..0..0..1..0....0..0..0..1..0..0 %e A219140 ..0..0..0..0..1..0....1..1..1..0..0..1....0..0..0..0..0..0....0..0..0..0..0..1 %K A219140 nonn %O A219140 1,1 %A A219140 _R. H. Hardin_ Nov 12 2012