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 A219413 #6 Jul 23 2025 00:25:58 %S A219413 1,65,1180,14737,193116,2633596,35794147,484744488,6565497170, %T A219413 88948580449,1205066512034,16325845207244,221177055650826, %U A219413 2996434981248536,40594730646344051,549964241638455480 %N A219413 Unmatched value maps: number of 4Xn binary arrays indicating the locations of corresponding elements not equal to any horizontal or antidiagonal neighbor in a random 0..2 4Xn array. %C A219413 Row 4 of A219410 %H A219413 R. H. Hardin, <a href="/A219413/b219413.txt">Table of n, a(n) for n = 1..210</a> %F A219413 Empirical: a(n) = 16*a(n-1) -65*a(n-2) +488*a(n-3) -1151*a(n-4) +5482*a(n-5) -7699*a(n-6) +23952*a(n-7) -11275*a(n-8) +4326*a(n-9) +78090*a(n-10) -207624*a(n-11) -138747*a(n-12) +498504*a(n-13) +170692*a(n-14) -650696*a(n-15) -185632*a(n-16) +542208*a(n-17) +117248*a(n-18) -278528*a(n-19) -32768*a(n-20) +65536*a(n-21) %e A219413 Some solutions for n=3 %e A219413 ..0..0..1....0..0..0....0..0..1....0..0..1....0..0..1....0..0..0....0..0..1 %e A219413 ..0..1..1....1..0..1....0..1..1....0..0..1....0..0..0....0..0..0....1..1..0 %e A219413 ..0..0..0....0..1..1....1..1..0....1..1..0....1..0..0....1..0..0....0..0..1 %e A219413 ..1..0..1....0..0..0....1..0..1....1..0..1....1..0..0....0..0..0....1..1..1 %K A219413 nonn %O A219413 1,2 %A A219413 _R. H. Hardin_ Nov 19 2012