A198909 Number of nX3 0..7 arrays with values 0..7 introduced in row major order and no element equal to any horizontal or vertical neighbor

2, 34, 2051, 269940, 54381563, 13088156547, 3352514013159, 876632051686733, 230783525290600476, 60892298359864756053, 16078352442288906898825, 4246466444504000973551502, 1121629692628918068552449185

Offset

1,1

Comments

Column 3 of A198914

Links

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

Formula

Empirical: a(n) = 431*a(n-1) -53038*a(n-2) +2570412*a(n-3) -55789402*a(n-4) +610919758*a(n-5) -3707175288*a(n-6) +13010264300*a(n-7) -26380804149*a(n-8) +29517406483*a(n-9) -16243626186*a(n-10) +3246286680*a(n-11)

Example

Some solutions with values 0 to 7 for n=4
..0..1..2....0..1..2....0..1..2....0..1..0....0..1..2....0..1..2....0..1..2
..3..4..0....3..4..5....3..0..4....2..3..4....1..3..4....3..0..4....3..4..0
..5..3..6....4..2..0....5..4..6....3..5..6....5..0..6....4..1..5....5..6..3
..0..1..7....1..6..7....6..1..7....7..4..0....0..1..7....6..7..4....3..5..7

Crossrefs

Sequence in context: A340863 A198977 A198718 * A207865 A216082 A165938

Adjacent sequences: A198906 A198907 A198908 * A198910 A198911 A198912

Keyword

nonn

Author

R. H. Hardin Oct 31 2011

Status

approved