A263969 Number of (n+1)X(2+1) arrays of permutations of 0..n*3+2 with each element having index change (+-,+-) 0,2 1,1 or 1,0.

20, 72, 1441, 13856, 189993, 2215960, 28027420, 340646784, 4224499865, 51860834624, 639939698625, 7875999490880, 97061605202532, 1195356109670056, 14726359450425633, 181392031870723936, 2234494271219028681

Offset

1,1

Comments

Column 2 of A263973.

Links

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

Formula

Empirical: a(n) = 7*a(n-1) +80*a(n-2) -135*a(n-3) -591*a(n-4) +752*a(n-5) -823*a(n-6) -415*a(n-7) +768*a(n-8) -81*a(n-9) -9*a(n-10)

Example

Some solutions for n=4
..2..3..0....4..3..0....2..5..0....2..3..0....2..5..4....3..4..0....2..3..0
..6..1..7....5..2..1....7..1..3....6..7..1....0..1..8....6..2..1....1..6..7
..8..4..5....8.11..6...10..4..6....8..4..5....3.11..6....9.11..5....8..5..4
.12.13.14....7.13.14...11.13..8...12.14.13...12..7.13....7..8.13...11.12.13
..9.10.11...10..9.12...14..9.12....9.10.11...14..9.10...14.10.12...14..9.10

Crossrefs

Cf. A263973.

Sequence in context: A083873 A240820 A143854 * A139241 A139232 A002292

Adjacent sequences: A263966 A263967 A263968 * A263970 A263971 A263972

Keyword

nonn

Author

R. H. Hardin, Oct 30 2015

Status

approved