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 A219436 #6 Jul 23 2025 00:27:13 %S A219436 4,18,78,329,1396,5925,25147,106731,452984,1922547,8159665,34631193, %T A219436 146981443,623817540,2647601755,11236931619,47691701338,202412762994, %U A219436 859078738551,3646095572825,15474731627673,65677740521441 %N A219436 Unmatched value maps: number of nX3 binary arrays indicating the locations of corresponding elements not equal to any horizontal, diagonal or antidiagonal neighbor in a random 0..1 nX3 array. %C A219436 Column 3 of A219441 %H A219436 R. H. Hardin, <a href="/A219436/b219436.txt">Table of n, a(n) for n = 1..210</a> %F A219436 Empirical: a(n) = 4*a(n-1) +a(n-2) +a(n-3) -2*a(n-4) -6*a(n-5) -3*a(n-6) -2*a(n-7) +5*a(n-8) +4*a(n-9) -2*a(n-10) -2*a(n-11) %e A219436 Some solutions for n=3 %e A219436 ..0..0..0....1..0..1....0..0..0....1..1..1....1..0..1....0..0..1....0..0..1 %e A219436 ..0..0..0....0..0..1....0..0..1....1..1..1....0..0..0....0..0..0....0..0..0 %e A219436 ..0..0..1....0..0..1....1..0..1....1..1..1....1..0..1....0..1..0....1..0..1 %K A219436 nonn %O A219436 1,1 %A A219436 _R. H. Hardin_ Nov 20 2012