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 A219437 #6 Jul 23 2025 00:27:19 %S A219437 7,39,281,1750,11283,72272,465400,2995163,19264275,123892153, %T A219437 796864416,5125652937,32969253934,212061980660,1364004538375, %U A219437 8773442559359,56431907119815,362977142538622,2334713999344447,15017169783617850 %N A219437 Unmatched value maps: number of nX4 binary arrays indicating the locations of corresponding elements not equal to any horizontal, diagonal or antidiagonal neighbor in a random 0..1 nX4 array. %C A219437 Column 4 of A219441 %H A219437 R. H. Hardin, <a href="/A219437/b219437.txt">Table of n, a(n) for n = 1..109</a> %F A219437 Empirical: a(n) = 8*a(n-1) -12*a(n-2) +6*a(n-3) +77*a(n-4) -184*a(n-5) -385*a(n-6) +137*a(n-7) +1716*a(n-8) +983*a(n-9) -3491*a(n-10) -525*a(n-11) +2567*a(n-12) -7634*a(n-13) +5725*a(n-14) +1489*a(n-15) +3574*a(n-16) +1516*a(n-17) -12799*a(n-18) +706*a(n-19) -3864*a(n-20) +7628*a(n-21) +8580*a(n-22) -6068*a(n-23) -1312*a(n-24) +160*a(n-25) +224*a(n-26) +48*a(n-27) %e A219437 Some solutions for n=3 %e A219437 ..1..0..0..0....0..0..1..1....0..0..0..0....0..0..0..1....1..0..0..0 %e A219437 ..0..0..0..1....1..0..0..0....1..0..0..1....0..0..0..0....0..0..0..0 %e A219437 ..1..0..0..1....1..0..0..0....1..0..0..0....1..0..0..1....0..0..1..1 %K A219437 nonn %O A219437 1,1 %A A219437 _R. H. Hardin_ Nov 20 2012