cp's OEIS Frontend

A207919 Number of 4Xn 0..1 arrays avoiding 0 0 0 and 1 0 1 horizontally and 0 1 0 and 1 0 1 vertically.

%I A207919 #7 Jul 22 2025 20:59:56
%S A207919 10,100,358,1309,4181,13759,46800,156135,518564,1734968,5800213,
%T A207919 19351425,64616191,215842982,720736677,2406625466,8036934640,
%U A207919 26838643787,89622848751,299284174725,999425753876,3337450100119,11144976639396
%N A207919 Number of 4Xn 0..1 arrays avoiding 0 0 0 and 1 0 1 horizontally and 0 1 0 and 1 0 1 vertically.
%C A207919 Row 4 of A207918
%H A207919 R. H. Hardin, <a href="/A207919/b207919.txt">Table of n, a(n) for n = 1..210</a>
%F A207919 Empirical: a(n) = a(n-1) +2*a(n-2) +18*a(n-3) +15*a(n-4) -6*a(n-5) -70*a(n-6) -96*a(n-7) -14*a(n-8) +154*a(n-9) +147*a(n-10) -113*a(n-12) -71*a(n-13) -9*a(n-14) +33*a(n-15) +12*a(n-16) -a(n-17) -7*a(n-18) +3*a(n-19) +a(n-20) +2*a(n-21) for n>22
%e A207919 Some solutions for n=4
%e A207919 ..0..0..1..1....1..0..0..1....0..1..0..0....0..1..1..0....1..1..0..0
%e A207919 ..0..1..0..0....1..1..1..1....0..0..1..0....0..1..1..1....1..0..0..1
%e A207919 ..0..1..0..0....1..1..1..1....0..0..1..1....0..1..1..1....0..0..1..1
%e A207919 ..0..1..0..0....1..0..0..1....0..1..1..1....0..1..1..1....0..0..1..0
%K A207919 nonn
%O A207919 1,1
%A A207919 _R. H. Hardin_ Feb 21 2012