A270051 Number of n X n 0..4 arrays with some element plus some horizontally or vertically adjacent neighbor totalling four exactly once.

0, 240, 385200, 4410058320, 446901694424400, 431802177781617762960, 4120579270516550893026428880, 396051988194462616335989531581823280, 388077749523667550173285586776073430011586480

Offset

1,2

Comments

Diagonal of A270058.

Links

Table of n, a(n) for n=1..9.

Example

Some solutions for n=2
..1..2. .0..3. .2..2. .1..1. .3..0. .1..2. .1..0. .0..4. .1..0. .2..3
..3..4. .0..1. .4..1. .4..3. .2..2. .4..0. .3..2. .0..2. .1..4. .2..3

Crossrefs

Cf. A270058.

Sequence in context: A047806 A184888 A158792 * A028678 A159950 A198481

Adjacent sequences: A270048 A270049 A270050 * A270052 A270053 A270054

Keyword

nonn

Author

R. H. Hardin, Mar 09 2016

Status

approved