A268880 Number of n X n binary arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling two exactly once.

0, 5, 84, 4133, 317966, 55491832, 19876401224, 15564645769042, 26617222097087230, 99905925686618815012, 832547140418699137884096, 15355865014207234684746438192, 632296902429868672596327438625296

Offset

1,2

Comments

Diagonal of A268886.

Links

R. H. Hardin, Table of n, a(n) for n = 1..26

Example

Some solutions for n=4
..1..1..0..0. .0..1..0..1. .0..0..0..1. .0..0..1..0. .0..0..0..0
..0..0..0..0. .0..1..0..0. .0..0..1..0. .1..0..1..0. .0..1..0..1
..0..0..0..0. .1..0..0..1. .1..0..1..0. .0..0..0..0. .0..1..0..0
..0..0..0..1. .0..0..0..1. .1..0..0..1. .1..0..1..1. .1..0..1..0

Crossrefs

Cf. A268886.

Sequence in context: A111911 A156720 A288163 * A367192 A048143 A216420

Adjacent sequences: A268877 A268878 A268879 * A268881 A268882 A268883

Keyword

nonn

Author

R. H. Hardin, Feb 15 2016

Status

approved