A197085 Number of nX3 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 4,3,2,0,1 for x=0,1,2,3,4

1, 5, 25, 96, 422, 1780, 7537, 31911, 135283, 573054, 2427879, 10286742, 43582082, 184647156, 782310778, 3314472134, 14042671183, 59495654829, 252069704002, 1067962669281, 4524717892087, 19170212756069, 81219883046173

Offset

1,2

Comments

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

Column 3 of A197090

Links

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

Formula

Empirical: a(n) = 3*a(n-1) +3*a(n-2) +10*a(n-3) -3*a(n-4) +2*a(n-5) +11*a(n-6) -15*a(n-7) -15*a(n-8) -2*a(n-9) +a(n-10) -2*a(n-11) +4*a(n-12) +2*a(n-13)

Example

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

Crossrefs

Sequence in context: A203340 A055343 A223945 * A273747 A201841 A146830

Adjacent sequences: A197082 A197083 A197084 * A197086 A197087 A197088

Keyword

nonn

Author

R. H. Hardin Oct 10 2011

Status

approved