A270054 Number of nX4 0..4 arrays with some element plus some horizontally or vertically adjacent neighbor totalling four exactly once.

240, 99840, 22911300, 4410058320, 779206497960, 130850370606120, 21244602958557060, 3367363526042121600, 524230216822482202860, 80480015854082855624040, 12218158166851049001563640

Offset

1,1

Comments

Column 4 of A270058.

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = 306*a(n-1) -27803*a(n-2) +685150*a(n-3) -6795613*a(n-4) +28270996*a(n-5) -41396356*a(n-6) for n>7

Example

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

Crossrefs

Cf. A270058.

Sequence in context: A001943 A052263 A218514 * A213696 A275459 A377220

Adjacent sequences: A270051 A270052 A270053 * A270055 A270056 A270057

Keyword

nonn

Author

R. H. Hardin, Mar 09 2016

Status

approved