A219305 Unchanging value maps: number of nX3 binary arrays indicating the locations of corresponding elements unequal to no horizontal or vertical neighbor in a random 0..2 nX3 array.

4, 18, 90, 423, 1958, 9233, 43725, 206269, 971794, 4583164, 21622807, 101988408, 481001317, 2268654909, 10700463129, 50469641870, 238042556300, 1122743524739, 5295505220276, 24976631418525, 117804014337453, 555630918690165

Offset: 1

Author

R. H. Hardin Nov 17 2012

Keywords

• nonn

Comments

Column 3 of A219310

Examples

			Some solutions for n=3
..1..0..1....0..0..0....1..1..1....1..1..1....0..0..1....0..0..0....0..0..1
..0..0..0....0..0..0....0..0..0....1..1..0....1..0..0....0..0..0....0..0..1
..0..1..0....0..0..1....0..0..0....1..0..0....1..0..0....1..1..0....1..0..0
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..95

Formula

Empirical: a(n) = 4*a(n-1) +a(n-2) +7*a(n-3) +35*a(n-4) -60*a(n-5) -68*a(n-6) +93*a(n-7) -72*a(n-8) -111*a(n-9) +101*a(n-10) -21*a(n-11) -28*a(n-12) +32*a(n-13) +2*a(n-14) +6*a(n-15) +8*a(n-16)