A197891 Number of nX3 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 3,3,0,1,1 for x=0,1,2,3,4

2, 12, 50, 180, 745, 3046, 12531, 52188, 217004, 902417, 3754101, 15614076, 64942049, 270106619, 1123416589, 4672495470, 19433743246, 80828359212, 336179618100, 1398231132013, 5815492663346, 24187671930371, 100600845478730

Offset

1,1

Comments

Every 0 is next to 0 3's, every 1 is next to 1 3's, every 2 is next to 2 0's, every 3 is next to 3 1's, every 4 is next to 4 1's

Column 3 of A197896

Links

R. H. Hardin, Table of n, a(n) for n = 1..200

Formula

Empirical: a(n) = 2*a(n-1) +3*a(n-2) +23*a(n-3) +13*a(n-4) +2*a(n-5) -95*a(n-6) -60*a(n-7) +119*a(n-8) +308*a(n-9) +152*a(n-10) -582*a(n-11) -876*a(n-12) -339*a(n-13) +656*a(n-14) +1015*a(n-15) +636*a(n-16) -148*a(n-17) -439*a(n-18) -245*a(n-19) +16*a(n-20) +32*a(n-21) -2*a(n-22)

Example

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

Crossrefs

Sequence in context: A323678 A028243 A003493 * A357782 A259802 A202789

Adjacent sequences: A197888 A197889 A197890 * A197892 A197893 A197894

Keyword

nonn

Author

R. H. Hardin Oct 19 2011

Status

approved