A198910 Number of nX4 0..7 arrays with values 0..7 introduced in row major order and no element equal to any horizontal or vertical neighbor

5, 500, 269940, 319608038, 481871809749, 769126451071174, 1243368053336112649, 2015791720035206825303, 3270193421121063659774745, 5305976942994216714747844079, 8609380449975858170849466245738

Offset

1,1

Comments

Column 4 of A198914

Links

R. H. Hardin, Table of n, a(n) for n = 1..123

Formula

Empirical: a(n) = 2296*a(n-1) -1239092*a(n-2) +252277904*a(n-3) -24632440060*a(n-4) +1347961370754*a(n-5) -44994493075469*a(n-6) +960046624478492*a(n-7) -13429762946315149*a(n-8) +124540876930445980*a(n-9) -765040702294085198*a(n-10) +3074302608489782520*a(n-11) -7884335188124038674*a(n-12) +12438514719451024794*a(n-13) -11471383995777540513*a(n-14) +5595786642970619820*a(n-15) -1099871574411268404*a(n-16)

Example

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

Crossrefs

Sequence in context: A012822 A124358 A198719 * A207866 A013305 A114066

Adjacent sequences: A198907 A198908 A198909 * A198911 A198912 A198913

Keyword

nonn

Author

R. H. Hardin Oct 31 2011

Status

approved