A301791 Number of 2Xn 0..1 arrays with every element equal to 0 or 1 horizontally or antidiagonally adjacent elements, with upper left element zero.

2, 5, 6, 9, 14, 22, 35, 56, 90, 145, 234, 378, 611, 988, 1598, 2585, 4182, 6766, 10947, 17712, 28658, 46369, 75026, 121394, 196419, 317812, 514230, 832041, 1346270, 2178310, 3524579, 5702888, 9227466, 14930353, 24157818, 39088170, 63245987

Offset

1,1

Comments

Row 2 of A301790.

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = 2*a(n-1) -a(n-3) for n>5.

Example

Some solutions for n=5
..0..0..1..0..0. .0..1..0..0..1. .0..1..0..1..1. .0..1..0..0..1
..1..0..1..1..0. .0..1..1..0..0. .0..1..0..0..1. .0..1..1..0..1

Crossrefs

Cf. A301790, A020706, A048577.

Sequence in context: A256249 A169779 A326118 * A051677 A122965 A350988

Adjacent sequences: A301788 A301789 A301790 * A301792 A301793 A301794

Keyword

nonn

Author

R. H. Hardin, Mar 26 2018

Status

approved