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 A219412 #6 Mar 20 2022 23:20:46 %S A219412 1,21,181,1199,8173,57097,398375,2773933,19314785,134507787,936720513, %T A219412 6523315045,45428247915,316361693953,2203138855813,15342630706087, %U A219412 106845881585421,744073337324881,5181717103636911,36085410931557557 %N A219412 Unmatched value maps: number of 3 X n binary arrays indicating the locations of corresponding elements not equal to any horizontal or antidiagonal neighbor in a random 0..2 3 X n array. %C A219412 Row 3 of A219410. %H A219412 R. H. Hardin, <a href="/A219412/b219412.txt">Table of n, a(n) for n = 1..210</a> %F A219412 Empirical: a(n) = 8*a(n-1) -14*a(n-2) +52*a(n-3) -48*a(n-4) +110*a(n-5) -51*a(n-6) +60*a(n-7) +52*a(n-8) -120*a(n-9) -20*a(n-10) +32*a(n-11). %e A219412 Some solutions for n=3 %e A219412 ..1..1..0....1..1..0....1..1..1....1..1..0....1..1..0....1..1..1....1..1..0 %e A219412 ..1..0..0....1..0..1....0..0..0....0..0..1....1..0..1....0..0..0....1..0..0 %e A219412 ..0..1..1....1..0..0....1..0..0....1..1..1....0..0..1....0..1..1....0..0..0 %Y A219412 Cf. A219410. %K A219412 nonn %O A219412 1,2 %A A219412 _R. H. Hardin_, Nov 19 2012