A264130 Number of (n+1) X (6+1) arrays of permutations of 0..n*7+6 with each element having index change +-(.,.) 0,0 0,2 or 1,2.

976, 53280, 2920000, 160564000, 8830490000, 485643650000, 26708584500000, 1468872605000000, 80782519512500000, 4442737533906250000, 244334008340781250000, 13437459939332812500000, 739010221489140625000000

Offset

1,1

Links

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

Formula

Empirical: a(n) = 60*a(n-1) - 300*a(n-2) + 1500*a(n-3) - 7500*a(n-4) + 3125*a(n-5).

Empirical g.f.: 16*x*(61 - 330*x + 1000*x^2 - 7250*x^3 + 3125*x^4) / ((1 - 5*x)*(1 - 55*x + 25*x^2 - 1375*x^3 + 625*x^4)). - Colin Barker, Jan 05 2019

Example

Some solutions for n=2:
..9..1..0.12..4..5..6....2.10.11.12.13..5..6....2..3..0.12.13..5..6
..7.10.11..8..2..3.13....9..8..0..1.20..3..4....7.17.18..1.11.10..4
.16.17.14.15.20.19.18...14.17..7.15.16.19.18...16.15.14..8..9.19.20

Crossrefs

Column 6 of A264131.

Sequence in context: A205252 A190400 A288917 * A282405 A077362 A077380

Adjacent sequences: A264127 A264128 A264129 * A264131 A264132 A264133

Keyword

nonn

Author

R. H. Hardin, Nov 03 2015

Status

approved