A303249 Number of nX3 0..1 arrays with every element equal to 1, 2, 3, 5 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.

1, 14, 49, 250, 1183, 5918, 28680, 141255, 691968, 3391358, 16627204, 81517689, 399591042, 1958997017, 9603668921, 47080079771, 230803211309, 1131476255863, 5546875012244, 27192677194545, 133307748424215, 653519804327678

Offset: 1

Author

R. H. Hardin, Apr 20 2018

Keywords

• nonn

Comments

Column 3 of A303254.

Examples

			Some solutions for n=5
..0..1..1. .0..0..0. .0..1..1. .0..1..0. .0..0..1. .0..0..1. .0..0..1
..1..0..1. .1..1..0. .1..0..1. .1..0..1. .0..1..1. .1..1..1. .0..1..0
..1..1..1. .0..1..1. .0..1..0. .1..1..1. .0..1..1. .0..0..0. .1..0..1
..0..0..1. .1..0..0. .1..0..0. .1..1..1. .0..0..1. .1..1..0. .1..1..0
..1..1..0. .0..1..1. .1..1..1. .1..0..0. .1..1..0. .1..0..1. .1..0..1
		

Links

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

Crossrefs

Cf. A303254.

Formula

Empirical: a(n) = 4*a(n-1) +6*a(n-2) +7*a(n-3) -61*a(n-4) -78*a(n-5) +115*a(n-6) +26*a(n-7) -126*a(n-8) -300*a(n-9) +380*a(n-10) -80*a(n-11) +144*a(n-12) -32*a(n-13) +128*a(n-14)