A264184 Number of (n+1)X(2+1) arrays of permutations of 0..n*3+2 with each element having index change +-(.,.) 0,0 1,-1 or 2,2.

4, 24, 81, 375, 1600, 6656, 28561, 120393, 509796, 2161720, 9150625, 38773295, 164249856, 695734272, 2947295521, 12484753489, 52886200900, 224030247000, 949005240561, 4020054131751, 17029223715904, 72136936615424

Offset

1,1

Comments

Column 2 of A264190.

Links

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

Formula

Empirical: a(n) = 4*a(n-1) +a(n-2) -17*a(n-4) +68*a(n-5) +17*a(n-6) +17*a(n-8) -68*a(n-9) -17*a(n-10) +a(n-12) -4*a(n-13) -a(n-14)

Example

Some solutions for n=4
..0..1..2....8..3..4....8..1..2....0..3..4....0..3..4....8..1..4....8..3..2
..3..6..5....1..2..5....3..6..5....1..2..5....1..2..5...11..2..5....1..6..5
..4..9..8...14..7..0....4..9..0....6..9..8....6..7..8...14..7..0....4..7..0
..7.10.13....9.10.11....7.12.11....7.10.11....9.12.11....9.10..3....9.12.11
.12.11.14...12.13..6...10.13.14...12.13.14...10.13.14...12.13..6...10.13.14

Crossrefs

Cf. A264190.

Sequence in context: A158494 A209456 A069145 * A354476 A211071 A212135

Adjacent sequences: A264181 A264182 A264183 * A264185 A264186 A264187

Keyword

nonn

Author

R. H. Hardin, Nov 06 2015

Status

approved