A266096 Number of n X 3 integer arrays with each element equal to the number of horizontal and antidiagonal neighbors exactly one smaller than itself.

4, 13, 64, 230, 1012, 3928, 16428, 65736, 269908, 1091720, 4454304, 18082796, 73622676, 299247292, 1217498296, 4950677020, 20137255328, 81894658192, 333086633092, 1354665687204, 5509630157292, 22408041160240, 91136102570276

Offset

1,1

Links

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

Formula

Empirical: a(n) = a(n-1) + 12*a(n-2) + 5*a(n-3) - 12*a(n-4) - 2*a(n-5).

Empirical g.f.: x*(4 + 9*x + 3*x^2 - 10*x^3 - 3*x^4) / (1 - x - 12*x^2 - 5*x^3 + 12*x^4 + 2*x^5). - Colin Barker, Jan 09 2019

Example

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

Crossrefs

Column 3 of A266101.

Sequence in context: A213093 A135312 A287145 * A005035 A340452 A222771

Adjacent sequences: A266093 A266094 A266095 * A266097 A266098 A266099

Keyword

nonn

Author

R. H. Hardin, Dec 21 2015

Status

approved