A264501 Number of (n+1)X(3+1) arrays of permutations of 0..n*4+3 with each element having directed index change -1,1 0,-1 0,1 or 1,0.

3, 14, 46, 149, 524, 1790, 6084, 20812, 71127, 242856, 829559, 2833848, 9679612, 33063445, 112939275, 385778601, 1317744028, 4501163516, 15375113297, 52518432516, 179392903112, 612771784386, 2093110937380, 7149665753285

Offset

1,1

Comments

Column 3 of A264506.

Links

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

Formula

Empirical: a(n) = 5*a(n-2) +17*a(n-3) +22*a(n-4) +5*a(n-5) -29*a(n-6) -44*a(n-7) -25*a(n-8) +11*a(n-9) +20*a(n-10) +11*a(n-11) -a(n-12) -2*a(n-13) -a(n-14)

Example

Some solutions for n=4
..1..4..3..2....1..2..3..6....1..0..3..6....1..4..3..2....1..2..5..6
..0..8..5..6....0..8..9.10....5..4..2.10....0..8..7.10....0..8..7..3
..9.10.11..7....4..5.11..7....9.12.13..7....9..5..6.14....4.12..9.14
.13.16.17.14...13.16.17.14....8.14.15.11...13.12.15.11...13.16.10.11
.12.18.19.15...12.18.19.15...17.16.19.18...17.16.19.18...17.18.19.15

Crossrefs

Cf. A264506.

Sequence in context: A180785 A123350 A027953 * A104196 A281869 A202144

Adjacent sequences: A264498 A264499 A264500 * A264502 A264503 A264504

Keyword

nonn

Author

R. H. Hardin, Nov 15 2015

Status

approved