A189437 Number of 5 X n array permutations with each element not moving, or moving one space N, SW or SE.

1, 20, 109, 841, 5680, 40065, 278105, 1940868, 13518605, 94223329, 656569824, 4575509121, 31884910129, 222195588532, 1548403370477, 10790295445561, 75193858910224, 524000231073025, 3651577819301001, 25446593414689700

Offset: 1

Author

R. H. Hardin, Apr 22 2011

Keywords

• nonn

Comments

Row 5 of A189435.

Examples

			Some solutions for 5 X 3:
..0..4..5....3..4..2....3..1..2....0..1..2....0..4..5....3..4..2....3..4..2
..6..2..1....1..0..5....6..0..8....3..4..8....6..2..1....1..0..8....1..0..8
..9..3..8....6..7.11....4..5.11....6..5.11....9..3.11....6..5.11....6..5.11
..7.13.14....9..8.14....9.10..7...12.13..7...12..8..7...12.13..7....7.13.14
.12.11.10...12.13.10...12.13.14...10..9.14...10.13.14...10..9.14...12..9.10
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..200

Crossrefs

Cf. A189435.

Formula

Empirical: a(n) = 10*a(n-1) -17*a(n-2) -47*a(n-3) +138*a(n-4) -75*a(n-5).

Empirical g.f.: x*(1 - x)*(1 + 11*x - 63*x^2 + 75*x^3) / (1 - 10*x + 17*x^2 + 47*x^3 - 138*x^4 + 75*x^5). - Colin Barker, May 02 2018