A268760 Number of n X n binary arrays with some element plus some horizontally, vertically, diagonally or antidiagonally adjacent neighbor totalling two exactly once.

0, 6, 56, 1148, 32056, 1552272, 127676872, 18045771274, 4495138018796, 1955829240647962, 1511334747222697904, 2064152526111916503300, 5022957354228609008158500, 21748481726801956896608976098

Offset

1,2

Comments

Diagonal of A268766.

Links

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

Example

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

Crossrefs

Cf. A268766.

Sequence in context: A185524 A122743 A241031 * A137032 A053421 A083696

Adjacent sequences: A268757 A268758 A268759 * A268761 A268762 A268763

Keyword

nonn

Author

R. H. Hardin, Feb 13 2016

Status

approved