A297721 Number of 2Xn 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 1, 2 or 4 neighboring 1s.

1, 10, 34, 83, 258, 865, 2651, 8041, 25114, 78356, 242335, 750668, 2331147, 7233125, 22428585, 69571574, 215837630, 669523807, 2076792418, 6442276953, 19984194983, 61990893369, 192295766302, 596503969480, 1850361240315, 5739832532268

Offset: 1

Author

R. H. Hardin, Jan 04 2018

Keywords

• nonn

Comments

Row 2 of A297720.

Examples

			Some solutions for n=7
..1..1..0..1..1..0..0. .0..0..1..0..1..1..1. .0..1..0..1..1..0..0
..1..1..0..0..0..1..1. .0..0..1..1..1..0..1. .1..0..0..1..0..0..0
		

Links

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

Crossrefs

Cf. A297720.

Formula

Empirical: a(n) = 4*a(n-1) -3*a(n-2) +3*a(n-3) -2*a(n-4) -24*a(n-5) +24*a(n-6)