A264056 Number of (n+1) X (4+1) arrays of permutations of 0..n*5+4 with each element having index change +-(.,.) 0,0 1,2 or 2,-2.

8, 216, 2592, 32400, 450000, 5760000, 74880000, 988650000, 12899250000, 168682500000, 2210850000000, 28926562500000, 378597656250000, 4956813281250000, 64881000000000000, 849285000000000000

Offset: 1

Author

R. H. Hardin, Nov 02 2015

Keywords

• nonn

Comments

Column 4 of A264059.

Examples

			Some solutions for n=4
..0..8.10.11..4....0..8..2.11.12....0..1.10..3.12....0..1..2..3..4
..5..6..7..1..2....5..6..7..1..9....5.13.15.16..9....5..6..7.16..9
.17..3.19.21.14...10..3..4.21.14....2.18..4..6..7...10.11.20.21.14
.15.16..9.18.12...22.16.24.18.19...22..8.24.11.19...22..8.17.18.19
.20.13.22.23.24...20.13.15.23.17...20.21.14.23.17...12.13.15.23.24
		

Links

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

Crossrefs

Cf. A264059.

Formula

Empirical: a(n) = 15*a(n-1) -25*a(n-2) +375*a(n-3) -5625*a(n-4) +9375*a(n-5) -15625*a(n-6) +234375*a(n-7) -390625*a(n-8) for n > 10.