A264624 Number of (n+1)X(4+1) arrays of permutations of 0..n*5+4 with each element having directed index change -2,0 -1,0 0,-1 or 1,1.

0, 9, 40, 108, 660, 4032, 19521, 89469, 449550, 2308554, 11454129, 56190429, 279105021, 1393420077, 6924459960, 34329680172, 170475275106, 847412314182, 4209930190557, 20905557159789, 103832641922175, 515806878937563

Offset

1,2

Comments

Column 4 of A264628.

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) +108*a(n-4) -36*a(n-5) -351*a(n-6) -1863*a(n-7) -4698*a(n-8) -4050*a(n-9) -243*a(n-10) +729*a(n-11) for n>12

Example

Some solutions for n=4
..5..2..3..4.14....5..2..3..4.14....5.11..3..4..9....5..2..3..4.14
..6..0..1..9.19....6..0..1..9.19....6..0..1..2.14....6..0..1..9.19
.15.16.17..7..8...11.16.13..7..8...20.12.17..7..8...15.12.13..7..8
.20.10.11.12.13...20.10.22.12.24...16.10.22.19.13...20.10.11.23.24
.21.22.23.24.18...21.15.23.17.18...21.15.23.24.18...21.22.16.17.18

Crossrefs

Cf. A264628.

Sequence in context: A003354 A063164 A165372 * A287324 A006414 A344053

Adjacent sequences: A264621 A264622 A264623 * A264625 A264626 A264627

Keyword

nonn

Author

R. H. Hardin, Nov 19 2015

Status

approved