A188953 Number of nX2 array permutations with each element moved no more than a city block distance of two.

2, 24, 362, 3969, 45288, 532224, 6187928, 71851073, 835579642, 9715691800, 112952196626, 1313218423169, 15268015911568, 177510903321088, 2063800528041456, 23994446285179649, 278967524405993266

Offset: 1

Author

R. H. Hardin Apr 14 2011

Keywords

• nonn

Comments

Column 2 of A188958

Examples

			Some solutions for 3X2
..3..2....1..0....1..2....3..2....1..2....3..1....4..0....1..5....0..1....1..5
..1..0....3..4....0..4....4..0....0..3....2..0....3..2....4..0....4..2....3..4
..4..5....2..5....3..5....5..1....5..4....4..5....5..1....2..3....3..5....0..2
		

Links

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

Formula

Empirical: a(n) = 10*a(n-1) +7*a(n-2) +156*a(n-3) -169*a(n-4) -410*a(n-5) -17*a(n-6) +576*a(n-7) -271*a(n-8) +310*a(n-9) -119*a(n-10) +68*a(n-11) -7*a(n-12) -6*a(n-13) +a(n-14)