A301904 Number of nX6 0..1 arrays with every element equal to 0, 2 or 3 horizontally or antidiagonally adjacent elements, with upper left element zero.

1, 6, 7, 40, 92, 532, 1999, 10150, 46226, 234484, 1167106, 6013755, 31027951, 161979950, 848039052, 4458470286, 23481316334, 123866264459, 653972874084, 3454977358732, 18260006314624, 96532215568355, 510408646716334

Offset: 1

Author

R. H. Hardin, Mar 28 2018

Keywords

• nonn

Comments

Column 6 of A301906.

Examples

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

Links

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

Crossrefs

Cf. A301906.

Formula

Empirical: a(n) = 3*a(n-1) +22*a(n-2) -23*a(n-3) -132*a(n-4) -102*a(n-5) -188*a(n-6) +202*a(n-7) +1241*a(n-8) +242*a(n-9) -1952*a(n-10) -662*a(n-11) +1583*a(n-12) +498*a(n-13) -772*a(n-14) -182*a(n-15) +220*a(n-16) +31*a(n-17) -22*a(n-18) -7*a(n-19) +a(n-20) for n>21