A301901 Number of n X n 0..1 arrays with every element equal to 0, 2 or 3 horizontally or antidiagonally adjacent elements, with upper left element zero.

1, 1, 3, 5, 12, 532, 8781, 952467, 81388360, 24626668920, 14235727386501, 14622615341736656, 38187293105036003115, 169994743921070851334774, 1720618701132822565695718755

Offset

1,3

Comments

Diagonal of A301906.

Links

Table of n, a(n) for n=1..15.

Example

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

Crossrefs

Cf. A301906.

Sequence in context: A352145 A276735 A099791 * A351225 A348744 A263829

Adjacent sequences: A301898 A301899 A301900 * A301902 A301903 A301904

Keyword

nonn

Author

R. H. Hardin, Mar 28 2018

Status

approved