A219151 Unchanging value maps: number of n X 3 binary arrays indicating the locations of corresponding elements unequal to no horizontal, antidiagonal or vertical neighbor in a random 0..1 n X 3 array.

4, 9, 32, 104, 360, 1234, 4224, 14421, 49292, 168568, 576373, 1970380, 6736149, 23030217, 78737741, 269190899, 920316854, 3146418782, 10757120910, 36776888782, 125734293267, 429865563961, 1469642274654, 5024473730153

Offset

1,1

Comments

Column 3 of A219156.

Links

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

Formula

Empirical: a(n) = 4*a(n-1) - 6*a(n-2) + 14*a(n-3) - 2*a(n-4) + a(n-5) + 11*a(n-6) - 9*a(n-7) + 6*a(n-8) - 3*a(n-9) - 4*a(n-10).

Empirical g.f.: x*(4 - 7*x + 20*x^2 - 26*x^3 + 18*x^4 - 16*x^5 + 3*x^6 + 2*x^7 - 3*x^8) / ((1 - x + x^2)*(1 - 3*x + 2*x^2 - 9*x^3 - 9*x^4 - x^5 - 3*x^6 + 7*x^7 + 4*x^8)). - Colin Barker, Jul 25 2018

Example

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

Crossrefs

Cf. A219156.

Sequence in context: A149118 A149119 A149120 * A057819 A129196 A119574

Adjacent sequences: A219148 A219149 A219150 * A219152 A219153 A219154

Keyword

nonn

Author

R. H. Hardin, Nov 12 2012

Status

approved