A264477 Number of (3+1)X(n+1) arrays of permutations of 0..n*4+3 with each element having directed index change 0,1 1,0 2,1 or -1,-1.

0, 4, 6, 16, 57, 160, 484, 1449, 4250, 12736, 37980, 112684, 335528, 998929, 2971856, 8844112, 26318889, 78319204, 233069764, 693574740, 2063954658, 6142018600, 18277651737, 54391278960, 161859683044, 481668191001, 1433366397054

Offset

1,2

Comments

Row 3 of A264476.

Links

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

Formula

Empirical: a(n) = 2*a(n-1) +10*a(n-3) -4*a(n-4) +8*a(n-5) -25*a(n-6) -4*a(n-8) +33*a(n-9) +4*a(n-10) -4*a(n-11) -10*a(n-12) -2*a(n-13) +a(n-15)

Example

Some solutions for n=4
..6..0..1..9..3....6..7..8..9..3....6..0..8..9..3....6..0..1..2..3
.11..5..2.14..4...11.12..2.14..4...11..5..2.14..4...11.12.13.14..4
.16.17.18.19.13....5..0..1.19.13...16.17..1.19.13....5.17.18.19..9
.10.15.12..7..8...10.15.16.17.18...10.15.12..7.18...10.15.16..7..8

Crossrefs

Cf. A264476.

Sequence in context: A038236 A223269 A264471 * A223357 A083009 A365111

Adjacent sequences: A264474 A264475 A264476 * A264478 A264479 A264480

Keyword

nonn

Author

R. H. Hardin, Nov 14 2015

Status

approved