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A209538 Number of nX3 array permutations with every element making zero or one right-handed knight moves (out 2, right 1) 1
1, 2, 16, 72, 243, 1125, 5000, 20480, 86528, 371293, 1565109, 6612354, 28063056, 118894600, 503284375, 2132531225, 9034882704, 38268370944, 162106085376, 686719856393, 2908947562937, 12322398111010, 52198820570000 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Column 3 of A209543

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..210

FORMULA

Empirical: a(n) = 4*a(n-1) +a(n-2) -72*a(n-5) +288*a(n-6) +72*a(n-7) +306*a(n-10) -1224*a(n-11) -306*a(n-12) +72*a(n-15) -288*a(n-16) -72*a(n-17) -a(n-20) +4*a(n-21) +a(n-22)

EXAMPLE

Some solutions for n=4

..0..1..7....0..1..7....0..1..2....0..1..2....0..1..7....0..6..7....5..6..2

..8..4..5....3..4.10....8..4.10....3..9.10....8..9..5....3..4.10....8..4..0

.11..2..3...11..2..8...11..7..3...11..7..8...11..2..3....1..2..8....1..7..3

..9.10..6....9..5..6....9..5..6....4..5..6....4.10..6....9..5.11....9.10.11

CROSSREFS

Sequence in context: A034579 A006733 A034580 * A006729 A007758 A207874

Adjacent sequences:  A209535 A209536 A209537 * A209539 A209540 A209541

KEYWORD

nonn

AUTHOR

R. H. Hardin Mar 10 2012

STATUS

approved

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Last modified June 15 16:13 EDT 2019. Contains 324142 sequences. (Running on oeis4.)