A189439 Number of 7Xn array permutations with each element not moving, or moving one space N, SW or SE.

1, 85, 1245, 26589, 493941, 9557077, 181540773, 3467525301, 66045131269, 1258981901653, 23988387057381, 457127606313333, 8710469146675973, 165979359956189589, 3162723963901817637, 60265641669988070325

Offset: 1

Author

R. H. Hardin Apr 22 2011

Keywords

• nonn

Comments

Row 7 of A189435

Examples

			Some solutions for 7X3
..0..1..2....3..1..2....3..1..2....0..1..2....0..1..2....3..4..2....0..1..2
..3..7..8....6..0..5....6..0..5....3..4..5....3..4..5....1..0..5....6..7..5
..6..5..4....9..7..4....4.10.11....6..7..8....6..7.11....6.10.11....4..3..8
..9.13.14...12..8.14....9..8..7...12.13.11...12..8.14....7..8.14....9.13.14
.12.11.10...15.11.10...12.13.17...10..9.14...15..9.10...12..9.17...12.11.10
.15.19.20...13.19.20...15.14.20...15.19.20...18.19.13...18.19.13...18.19.17
.18.17.16...18.17.16...18.19.16...18.17.16...16.17.20...16.15.20...16.15.20
		

Links

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

Formula

Empirical: a(n) = 23*a(n-1) +26*a(n-2) -2256*a(n-3) +3272*a(n-4) +63936*a(n-5) -101752*a(n-6) -714624*a(n-7) +1041216*a(n-8) +3522752*a(n-9) -4444032*a(n-10) -7691264*a(n-11) +5545472*a(n-12) [phone]*a(n-13) -4947968*a(n-14) -4030464*a(n-15)