A267618 - OEIS

A267618

Number of 2Xn arrays containing n copies of 0..2-1 with every element equal to at least one horizontal or antidiagonal neighbor and the top left element equal to 0.

%I #6 Aug 12 2016 06:54:01

%S 0,1,2,4,12,34,112,340,1073,3335,10487,32890,103628,326677,1032139,

%T 3264645,10341541,32795480,104121342,330894709,1052560143,3350969989,

%U 10676723143,34042525681,108617828200,346780908546,1107812557123

%N Number of 2Xn arrays containing n copies of 0..2-1 with every element equal to at least one horizontal or antidiagonal neighbor and the top left element equal to 0.

%C Row 2 of A267617.

%H R. H. Hardin, <a href="/A267618/b267618.txt">Table of n, a(n) for n = 1..210</a>

%e Some solutions for n=5

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

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

%Y Cf. A267617.

%K nonn

%O 1,3

%A _R. H. Hardin_, Jan 18 2016