A269824 Number of nX3 0..4 arrays with some element plus some horizontally, diagonally, antidiagonally or vertically adjacent neighbor totalling four exactly once.

40, 3096, 103296, 3200604, 90748696, 2472983556, 65284613232, 1686961414812, 42866673833128, 1075244105809044, 26689182058679264, 656784781178376396, 16046367933842361752, 389645465813128015044, 9411830636459978769552

Offset

1,1

Comments

Column 3 of A269829.

Links

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

Formula

Empirical: a(n) = 34*a(n-1) +37*a(n-2) -7276*a(n-3) +2525*a(n-4) +294806*a(n-5) -785545*a(n-6) -1242552*a(n-7) +4983512*a(n-8) +814900*a(n-9) -9636844*a(n-10) +1645224*a(n-11) +5010412*a(n-12) -1220112*a(n-13) -975664*a(n-14) +242688*a(n-15) +70464*a(n-16) -11520*a(n-17) -2304*a(n-18) for n>19

Example

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

Crossrefs

Cf. A269829.

Sequence in context: A221658 A188154 A268151 * A178721 A059948 A229604

Adjacent sequences: A269821 A269822 A269823 * A269825 A269826 A269827

Keyword

nonn

Author

R. H. Hardin, Mar 05 2016

Status

approved