A264000 Number of (n+1) X (3+1) arrays of permutations of 0..n*4+3 with each element having index change (+-,+-) 0,0 1,2 or 1,0.

81, 1089, 34225, 833569, 22819729, 604028929, 16226938225, 434018757601, 11630234757969, 311473399634881, 8343631521197361, 223489568111529889, 5986489381143819025, 160355199781238376321, 4295319737094655966449

Offset

1,1

Links

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

Formula

Empirical: a(n) = 29*a(n-1) + 36*a(n-2) - 2832*a(n-3) + 6656*a(n-4) + 24576*a(n-5) - 65536*a(n-6).

Empirical g.f.: x*(81 - 1260*x - 272*x^2 + 31232*x^3 - 40960*x^4 - 65536*x^5) / ((1 - 33*x + 176*x^2 - 256*x^3)*(1 + 4*x - 80*x^2 - 256*x^3)). - Colin Barker, Jan 03 2019

Example

Some solutions for n=3:
..0..5..4..7....4..5..2..3....0..7..6..3....0..1..6..7....0..5..4..3
.10..3..2..1....0.11..6..1....4.11..2..1...10..3..2.11....2..1..6..9
..6..9.14.11...12.15.14..7...14..5.12.13....4.15.12..5...12.15.14..7
.12.13..8.15...10.13..8..9...10..9..8.15....8.13.14..9....8.13.10.11

Crossrefs

Column 3 of A264003.

Sequence in context: A183807 A264203 A236047 * A236781 A237059 A374144

Adjacent sequences: A263997 A263998 A263999 * A264001 A264002 A264003

Keyword

nonn

Author

R. H. Hardin, Oct 31 2015

Status

approved