A266102 Number of 2Xn integer arrays with each element equal to the number of horizontal and antidiagonal neighbors exactly one smaller than itself.

1, 5, 13, 36, 100, 233, 680, 2201, 6508, 18689, 55362, 167587, 511996, 1565487, 4772336, 14577149, 44758492, 137803612, 424402090, 1307283605, 4029557464, 12430685471, 38368732042, 118459868528, 365782453416, 1129647978659

Offset: 1

Author

R. H. Hardin, Dec 21 2015

Keywords

• nonn

Comments

Row 2 of A266101.

Examples

			Some solutions for n=4
..0..1..2..0....1..0..1..1....1..0..0..1....0..0..1..2....0..0..1..1
..2..1..0..1....1..1..0..1....1..2..1..0....0..1..1..0....1..2..0..0
		

Links

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

Crossrefs

Cf. A266101.

Formula

Empirical: a(n) = 3*a(n-1) -a(n-2) +6*a(n-3) +4*a(n-4) -8*a(n-5) -15*a(n-6) -135*a(n-7) -149*a(n-8) -34*a(n-9) +87*a(n-10) +139*a(n-11) +59*a(n-12) -2*a(n-13) -15*a(n-14) -9*a(n-15) -a(n-16) for n>19