A189430 Number of nX4 array permutations with each element not moving, or moving one space N, SW or SE

1, 5, 29, 140, 841, 4653, 26589, 151081, 859264, 4891841, 27832869, 158410277, 901506585, 5130598532, 29198860965, 166174106629, 945717892865, 5382196223185, 30630747783536, 174323378425833, 992095956013449

Offset

1,2

Comments

Column 4 of A189435

Links

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

Formula

Empirical: a(n) = 4*a(n-1) +6*a(n-2) +15*a(n-3) +32*a(n-4) +31*a(n-5) -139*a(n-6) -38*a(n-7) -687*a(n-8) -1137*a(n-9) -2150*a(n-10) -2761*a(n-11) -2277*a(n-12) -6462*a(n-13) -713*a(n-14) -1533*a(n-15) +1533*a(n-17) +713*a(n-18) +6462*a(n-19) +2277*a(n-20) +2761*a(n-21) +2150*a(n-22) +1137*a(n-23) +687*a(n-24) +38*a(n-25) +139*a(n-26) -31*a(n-27) -32*a(n-28) -15*a(n-29) -6*a(n-30) -4*a(n-31) +a(n-32)

Example

Some solutions for 3X4
..0..5..6..3....0..1..2..3....0..1..6..3....0..5..6..3....4..1..6..3
..1..9.10..2....8..9..6..7....8..9.10..2....4..2..1..7....8..0.10..2
..8..4..7.11....5..4.10.11....5..4..7.11....8..9.10.11....5..9..7.11

Crossrefs

Sequence in context: A268957 A146053 A163082 * A273078 A060963 A107002

Adjacent sequences: A189427 A189428 A189429 * A189431 A189432 A189433

Keyword

nonn

Author

R. H. Hardin Apr 22 2011

Status

approved