A221630 Equals one maps: number of nX3 binary arrays indicating the locations of corresponding elements equal to exactly one of their horizontal, diagonal and antidiagonal neighbors in a random 0..3 nX3 array

4, 37, 395, 3575, 30145, 247495, 2003761, 16117917, 129240286, 1034701626, 8277555240, 66195137589, 529260702037, 4231296692315, 33826548373479, 270415884605246, 2161732368363020, 17281016582013451, 138145098446018337

Offset

1,1

Comments

Column 3 of A221632

Links

R. H. Hardin, Table of n, a(n) for n = 1..177

Formula

Empirical: a(n) = 15*a(n-1) -69*a(n-2) +100*a(n-3) +61*a(n-4) -209*a(n-5) -378*a(n-6) +996*a(n-7) +544*a(n-8) -1560*a(n-9) -491*a(n-10) +1328*a(n-11) -180*a(n-12) -112*a(n-13) +124*a(n-14) +32*a(n-15) for n>17

Example

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

Crossrefs

Sequence in context: A326014 A220914 A070768 * A235135 A316877 A349254

Adjacent sequences: A221627 A221628 A221629 * A221631 A221632 A221633

Keyword

nonn

Author

R. H. Hardin Jan 21 2013

Status

approved