A264578 Number of (n+1)X(3+1) arrays of permutations of 0..n*4+3 with each element having directed index change 1,0 0,-1 1,2 or -1,1.

0, 4, 4, 6, 25, 68, 112, 281, 856, 1674, 3988, 10508, 23724, 55897, 136144, 325584, 765361, 1829400, 4401652, 10407276, 24816024, 59395330, 141247593, 336608388, 803177056, 1914674361, 4562063424, 10876904302, 25937972164, 61813285608

Offset

1,2

Comments

Column 3 of A264583.

Links

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

Formula

Empirical: a(n) = 2*a(n-2) +10*a(n-3) +4*a(n-4) -4*a(n-5) -33*a(n-6) +4*a(n-7) +25*a(n-9) -8*a(n-10) +4*a(n-11) -10*a(n-12) -2*a(n-14) +a(n-15)

Example

Some solutions for n=4
..1..2..5..6....1..2..3..6....1..2..3..6....1..2..5..6....1..2..5..6
..0..8..7..3....0..8..7.10....0..8..7.10....0..8..7..3....0..8..7..3
..9.12..4.14....4..5.11.14....9..5..4.14....4.12.11.14....4.10.11.14
.13.16.10.11...13.16.17..9...13.16.17.11...13.16.10..9...13.16.17..9
.17.18.19.15...12.18.19.15...12.18.19.15...17.18.19.15...12.18.19.15

Crossrefs

Cf. A264583.

Sequence in context: A019176 A143391 A158661 * A261146 A368304 A365063

Adjacent sequences: A264575 A264576 A264577 * A264579 A264580 A264581

Keyword

nonn

Author

R. H. Hardin, Nov 18 2015

Status

approved