A304005 Number of nX3 0..1 arrays with every element unequal to 0, 2, 3 or 5 king-move adjacent elements, with upper left element zero.

1, 7, 13, 21, 27, 53, 99, 197, 371, 713, 1365, 2645, 5105, 9857, 19079, 36861, 71379, 138165, 267465, 518201, 1003521, 1944649, 3767939, 7302057, 14153291, 27432325, 53179669, 103092661, 199871009, 387518385, 751360183, 1456897269, 2824988675

Offset: 1

Author

R. H. Hardin, May 04 2018

Keywords

• nonn

Comments

Column 3 of A304010.

Examples

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

Links

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

Crossrefs

Cf. A304010.

Formula

Empirical: a(n) = a(n-1) +5*a(n-2) -a(n-3) -12*a(n-4) -2*a(n-5) +10*a(n-6) +2*a(n-7) +a(n-8) +7*a(n-9) -3*a(n-10) -19*a(n-11) -2*a(n-12) +2*a(n-13) -4*a(n-14) +10*a(n-15) +6*a(n-16) for n>17