A264502 Number of (n+1) X (4+1) arrays of permutations of 0..n*5+4 with each element having directed index change -1,1 0,-1 0,1 or 1,0.

6, 38, 211, 1224, 7177, 41622, 241432, 1401492, 8132167, 47182878, 273763030, 1588400232, 9215985850, 53471653248, 310245343849, 1800059031396, 10444031588569, 60596786462766, 351585536645329, 2039916562746852

Offset

1,1

Links

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

Formula

Empirical: a(n) = 6*a(n-1) - 5*a(n-2) + 36*a(n-3) - 72*a(n-4) - 243*a(n-6) for n>7.

Empirical g.f.: x*(6 + 2*x + 13*x^2 - 68*x^3 - 48*x^4 - 180*x^5 + 171*x^6) / ((1 - x - 9*x^3)*(1 - 5*x - 27*x^3)). - Colin Barker, Jan 08 2019

Example

Some solutions for n=4:
..1..5..6..4..3....1..2..6..4..3....1..2..6..4..8....1..0..3..4..8
..0..7..2..9..8....0..7.11..9..8....0.10.11..3.13....6.10..2..7.13
.11.15.13.12.18....5.12.16.17.13....5.12..7.14..9....5.15.11.12..9
.10.20.16.19.14...10.20.18.19.14...16.20.21.17.18...16.20.18.17.14
.21.22.17.24.23...15.22.21.24.23...15.22.23.24.19...21.22.23.24.19

Crossrefs

Column 4 of A264506.

Sequence in context: A189492 A281803 A288030 * A263331 A026296 A037499

Adjacent sequences: A264499 A264500 A264501 * A264503 A264504 A264505

Keyword

nonn

Author

R. H. Hardin, Nov 15 2015

Status

approved