A269038 Number of 4Xn 0..2 arrays with some element plus some horizontally, diagonally or antidiagonally adjacent neighbor totalling two exactly once.

0, 504, 2136, 18384, 115656, 785124, 4998648, 31834476, 198736752, 1231177296, 7552688064, 46020487500, 278641166280, 1678349335044, 10062618187272, 60089435895360, 357550261665528, 2120806295463156, 12543856834626072

Offset: 1

Author

R. H. Hardin, Feb 18 2016

Keywords

• nonn

Comments

Row 4 of A269035.

Examples

			Some solutions for n=4
..0..1..0..1. .2..2..2..1. .2..2..2..2. .1..0..0..2. .2..2..1..2
..2..1..2..1. .2..2..2..2. .1..2..2..1. .1..0..1..0. .2..2..2..2
..0..1..0..1. .2..1..2..1. .1..2..1..2. .0..0..1..0. .2..2..2..2
..0..0..2..1. .0..2..2..1. .1..2..1..2. .1..0..1..0. .2..2..1..1
		

Links

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

Crossrefs

Cf. A269035.

Formula

Empirical: a(n) = 6*a(n-1) +23*a(n-2) -102*a(n-3) -288*a(n-4) +250*a(n-5) +787*a(n-6) -238*a(n-7) -741*a(n-8) +124*a(n-9) +196*a(n-10) -16*a(n-11) -16*a(n-12) for n>14