A264485 Number of (n+1)X(2+1) arrays of permutations of 0..n*3+2 with each element having directed index change 2,-1 1,0 2,1 0,-1 -2,-2 or -1,0.

1, 1, 12, 16, 214, 324, 2960, 6442, 42656, 113575, 636361, 1918550, 9612512, 31689325, 147107038, 515046002, 2273096344, 8287463026, 35352586169, 132498950637, 552353463562, 2109344649645, 8657596384451, 33484770583688

Offset

1,3

Comments

Column 2 of A264490.

Links

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

Formula

Empirical: a(n) = 20*a(n-2) +8*a(n-3) -102*a(n-4) -38*a(n-5) +337*a(n-6) +39*a(n-7) -2538*a(n-8) -1048*a(n-9) +9220*a(n-10) +3898*a(n-11) -10078*a(n-12) +719*a(n-13) +55039*a(n-14) +28538*a(n-15) -139480*a(n-16) -52428*a(n-17) -19106*a(n-18) -17134*a(n-19) -99749*a(n-20) -71330*a(n-21) +298006*a(n-22) +77280*a(n-23) +114868*a(n-24) +14464*a(n-25) +78816*a(n-26) +80368*a(n-27) -280704*a(n-28) -11136*a(n-29) -107712*a(n-30) -5568*a(n-31) -33408*a(n-32) -31104*a(n-33) +93312*a(n-34) -13824*a(n-35) +41472*a(n-36)

Example

Some solutions for n=4
..8..4..5....3..4..5....8..4..5....3..2..5....8..4..5....8..4..5....3..4..5
..0..1..2....6..1..2....0..7..2....6..7..8....6..1..2....0..7..2....0..1..2
..9.10.11...14..0.11....9.10..1...14..0..1....9..0.11....3.10..1...14.10.11
.12..3.14...12.13..8...12..3.14...12.13..4...12..3.14...12.13.14...12.13..8
.13..6..7....9.10..7...13..6.11....9.10.11...13.10..7....9..6.11....9..6..7

Crossrefs

Cf. A264490.

Sequence in context: A060669 A166644 A264492 * A278034 A087657 A248478

Adjacent sequences: A264482 A264483 A264484 * A264486 A264487 A264488

Keyword

nonn

Author

R. H. Hardin, Nov 14 2015

Status

approved