A264651 Number of (n+1)X(4+1) arrays of permutations of 0..n*5+4 with each element having directed index change 1,1 2,2 -1,0 or 0,-1.

0, 9, 22, 112, 716, 3100, 14871, 73900, 349328, 1679736, 8094842, 38736132, 186037049, 893328303, 4285139965, 20570385615, 98729249057, 473793905479, 2274044573512, 10914002589581, 52379748049810, 251394035040131

Offset

1,2

Comments

Column 4 of A264655.

Links

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

Formula

Empirical: a(n) = 3*a(n-1) +36*a(n-3) -18*a(n-4) +186*a(n-5) +83*a(n-6) +144*a(n-7) +684*a(n-8) -1872*a(n-9) +508*a(n-10) -5048*a(n-11) -3240*a(n-12) +720*a(n-13) -95040*a(n-14) +3072*a(n-15) +3456*a(n-16) +13824*a(n-18) for n>21

Example

Some solutions for n=4
..1..2..7..4..9....1..2..3..4..9....1..6..7..4..9....1..2..3..4..9
..6..0.12.13..3...10..0..8.13.14...10.11..8..2..3...10.11..8.13.14
.15.16.17.14..8...15.16..6..7.19...15.12..0.14.19...15.16..0.18.19
.20.10..5.19.24...20.17..5.12.24...20.17..5.23.13...20.17..5..6..7
.21.22.23.11.18...21.22.23.11.18...21.22.16.24.18...21.22.23.24.12

Crossrefs

Cf. A264655.

Sequence in context: A287497 A232024 A327150 * A113519 A300462 A123833

Adjacent sequences: A264648 A264649 A264650 * A264652 A264653 A264654

Keyword

nonn

Author

R. H. Hardin, Nov 20 2015

Status

approved