A301993 Number of n X n 0..1 arrays with every element equal to 1, 2 or 4 horizontally or antidiagonally adjacent elements, with upper left element zero.

0, 2, 5, 74, 2856, 100176, 15243860, 3267873712, 1423142192108, 1493258497764034, 2656316754272813006, 10809582885066864547012, 85481211759186744525328998, 1368540960166632565900365694716

Offset

1,2

Comments

Diagonal of A301999.

Links

Table of n, a(n) for n=1..14.

Example

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

Crossrefs

Cf. A301999.

Sequence in context: A042693 A328746 A172037 * A128297 A183291 A372482

Adjacent sequences: A301990 A301991 A301992 * A301994 A301995 A301996

Keyword

nonn

Author

R. H. Hardin, Mar 30 2018

Status

approved