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 A207754 #7 Jul 22 2025 20:47:12 %S A207754 14,196,798,3249,8778,23716,51590,112225,213060,404496,698964,1207801, %T A207754 1947428,3139984,4800348,7338681,10754730,15760900,22315370,31595641, %U A207754 43472814,59814756,80333058,107889769,141927968,186704896,241237920 %N A207754 Number of 5Xn 0..1 arrays avoiding 0 0 1 and 0 1 1 horizontally and 0 0 1 and 1 0 0 vertically. %C A207754 Row 5 of A207752 %H A207754 R. H. Hardin, <a href="/A207754/b207754.txt">Table of n, a(n) for n = 1..210</a> %F A207754 Empirical: a(n) = 2*a(n-1) +6*a(n-2) -14*a(n-3) -14*a(n-4) +42*a(n-5) +14*a(n-6) -70*a(n-7) +70*a(n-9) -14*a(n-10) -42*a(n-11) +14*a(n-12) +14*a(n-13) -6*a(n-14) -2*a(n-15) +a(n-16) %e A207754 Some solutions for n=4 %e A207754 ..1..1..0..0....1..1..0..0....1..0..0..0....1..1..1..1....1..0..0..0 %e A207754 ..0..1..0..1....1..0..1..0....0..1..0..0....1..1..0..0....0..1..0..1 %e A207754 ..1..1..0..1....0..1..0..0....1..0..0..0....1..1..1..1....1..0..0..0 %e A207754 ..1..1..0..1....1..0..1..0....1..1..0..0....0..1..0..0....1..1..0..1 %e A207754 ..1..0..0..0....1..1..1..0....1..1..0..0....1..1..1..1....0..1..0..0 %K A207754 nonn %O A207754 1,1 %A A207754 _R. H. Hardin_ Feb 19 2012