A218051 Number of n X 1 arrays of the minimum value of corresponding elements and their horizontal, vertical, diagonal or antidiagonal neighbors in a random 0..3 n X 1 array.

4, 4, 16, 36, 94, 236, 602, 1528, 3882, 9858, 25038, 63592, 161514, 410218, 1041884, 2646208, 6720920, 17069998, 43354902, 110114102, 279671154, 710317326, 1804085608, 4582071648, 11637685314, 29557748082, 75071670020, 190669317026

Offset

1,1

Comments

Column 1 of A218056.

Links

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

Formula

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

Empirical g.f.: 2*x*(2 - 2*x + 2*x^2 - x^4) / (1 - 2*x - x^2 - 2*x^4 - x^5). - Colin Barker, Feb 19 2018

Example

All solutions for n=3:
..2....0....3....2....3....2....3....2....0....1....1....1....1....3....0....0
..1....0....3....2....2....2....1....0....0....1....1....1....0....0....0....0
..1....0....3....3....2....2....1....0....2....2....3....1....0....0....1....3

Crossrefs

Sequence in context: A158101 A038234 A099462 * A092266 A257606 A219398

Adjacent sequences: A218048 A218049 A218050 * A218052 A218053 A218054

Keyword

nonn

Author

R. H. Hardin, Oct 19 2012

Status

approved