A268998 Number of 4Xn binary arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling two not more than once.

16, 126, 849, 6009, 37987, 244397, 1506570, 9258784, 55904997, 335264275, 1991983545, 11763490813, 69051103048, 403375829894, 2346089237885, 13593697842329, 78497992061491, 451930855824889, 2594820580805818

Offset: 1

Author

R. H. Hardin, Feb 17 2016

Keywords

• nonn

Comments

Row 4 of A268995.

Examples

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

Links

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

Crossrefs

Cf. A268995.

Formula

Empirical: a(n) = 2*a(n-1) +39*a(n-2) +14*a(n-3) -482*a(n-4) -1102*a(n-5) -111*a(n-6) +1758*a(n-7) +982*a(n-8) -1114*a(n-9) -743*a(n-10) +394*a(n-11) +206*a(n-12) -90*a(n-13) -17*a(n-14) +10*a(n-15) -a(n-16)