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 A219408 #6 Jul 23 2025 00:25:37 %S A219408 21,1261,57097,2633596,121641579,5618116265,259468310384, %T A219408 11983486642214,553453107750115,25561051456876291,1180528707338785094, %U A219408 54522328912450097473,2518095766994664668337,116297422017630310505820 %N A219408 Unmatched value maps: number of nX6 binary arrays indicating the locations of corresponding elements not equal to any horizontal or antidiagonal neighbor in a random 0..2 nX6 array. %C A219408 Column 6 of A219410 %H A219408 R. H. Hardin, <a href="/A219408/b219408.txt">Table of n, a(n) for n = 1..210</a> %F A219408 Empirical: a(n) = 21*a(n-1) +950*a(n-2) +9306*a(n-3) +26031*a(n-4) -50016*a(n-5) -214765*a(n-6) +276749*a(n-7) +349461*a(n-8) -523220*a(n-9) -71125*a(n-10) +294741*a(n-11) -112428*a(n-12) +11664*a(n-13) for n>14 %e A219408 Some solutions for n=3 %e A219408 ..1..0..1..1..0..0....0..0..1..0..1..0....1..0..1..0..0..0....1..0..1..0..0..1 %e A219408 ..0..0..0..1..1..1....0..0..0..1..0..1....0..1..0..0..0..0....0..0..1..0..0..1 %e A219408 ..0..1..0..0..0..0....1..1..1..0..0..0....1..0..0..0..0..0....1..1..0..0..1..1 %K A219408 nonn %O A219408 1,1 %A A219408 _R. H. Hardin_ Nov 19 2012