A207770 - OEIS

%I #11 Mar 01 2023 15:30:41

%S 10,100,292,828,2514,7164,20104,57458,165182,475522,1374786,3988072,

%T 11586166,33700098,98126672,285904744,833354524,2429866940,7086585498,

%U 20670718296,60300595980,175923202614,513272786306,1497579333338

%N Number of n X 4 0..1 arrays avoiding 0 0 0 and 1 1 1 horizontally and 0 0 1 and 0 1 0 vertically.

%C Column 4 of A207774.

%H R. H. Hardin, <a href="/A207770/b207770.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 5*a(n-1) -8*a(n-2) +17*a(n-3) -46*a(n-4) +40*a(n-5) -41*a(n-6) +115*a(n-7) -38*a(n-8) +2*a(n-9) -144*a(n-10) -18*a(n-11) +52*a(n-12) +133*a(n-13) +44*a(n-14) -42*a(n-15) -86*a(n-16) -34*a(n-17) +16*a(n-18) +26*a(n-19) +16*a(n-20) -2*a(n-21) -3*a(n-22) -2*a(n-23) -a(n-24) for n>25.

%e Some solutions for n=4

%e ..1..0..1..1....1..1..0..0....0..1..0..0....1..0..0..1....0..0..1..1

%e ..1..0..0..1....0..0..1..1....1..0..0..1....1..0..1..1....0..1..1..0

%e ..1..0..1..1....1..0..1..1....1..1..0..1....0..0..1..1....0..1..0..0

%e ..0..0..1..0....1..0..0..1....1..1..0..1....0..0..1..0....0..0..1..0

%Y Cf. A207774.

%K nonn

%O 1,1

%A _R. H. Hardin_, Feb 20 2012