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A189430
Number of nX4 array permutations with each element not moving, or moving one space N, SW or SE
1
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
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
KEYWORD
nonn
AUTHOR
R. H. Hardin Apr 22 2011
STATUS
approved