A301825 - OEIS

%I #4 Mar 27 2018 10:15:37

%S 0,13,8,68,299,1351,6653,30441,146175,682879,3234177,15226483,

%T 71859897,338825989,1598126524,7536923120,35546600366,167645751951,

%U 790663538862,3728968861295,17586797354805,82943890400479,391184964947659

%N Number of 4Xn 0..1 arrays with every element equal to 1 or 2 horizontally or antidiagonally adjacent elements, with upper left element zero.

%C Row 4 of A301823.

%H R. H. Hardin, <a href="/A301825/b301825.txt">Table of n, a(n) for n = 1..210</a>

%H R. H. Hardin, <a href="/A301825/a301825.txt">Empirical recurrence of order 66</a>

%F Empirical recurrence of order 66 (see link above)

%e Some solutions for n=5

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

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

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

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

%Y Cf. A301823.

%K nonn

%O 1,2

%A _R. H. Hardin_, Mar 27 2018