A263812 Number of (n+1) X (2+1) arrays of permutations of 0..n*3+2 with each element having index change (+-,+-) 0,0 0,1 0,2 or 1,0.

82, 948, 11305, 134028, 1590733, 18875976, 223995034, 2658056430, 31542099589, 374297467464, 4441638405853, 52707146757882, 625454634139210, 7422020035297392, 88074143832191077, 1045140645645600804

Offset

1,1

Links

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

Formula

Empirical: a(n) = 10*a(n-1) + 23*a(n-2) - 10*a(n-3) -a(n-4).

Empirical g.f.: x*(82 + 128*x - 61*x^2 - 6*x^3) / (1 - 10*x - 23*x^2 + 10*x^3 + x^4). - Colin Barker, Jan 03 2019

Example

Some solutions for n=4:
..2..0..1....2..0..1....0..2..1....2..1..0....1..0..2....0..4..1....2..0..1
..3..5..4....6..3..4....3..7..5....5..3..8....5..7..4....3..5..2....3..5..4
..7..6.11....7..8..5....8..4..6....9..4..7....3..8..6....7..8.11....9..6..8
.10.13..8...10.11..9...12..9.14....6.11.10...12.13.14....6..9.10...10..7.11
..9.12.14...12.13.14...13.10.11...13.12.14....9.10.11...12.14.13...14.13.12

Crossrefs

Column 2 of A263816.

Sequence in context: A083386 A356536 A282159 * A160154 A093282 A085439

Adjacent sequences: A263809 A263810 A263811 * A263813 A263814 A263815

Keyword

nonn

Author

R. H. Hardin, Oct 27 2015

Status

approved