A217880 Number of n element 0..2 arrays with each element the minimum of 5 adjacent elements of a random 0..2 array of n+4 elements.

3, 9, 22, 46, 86, 148, 244, 402, 685, 1223, 2263, 4243, 7910, 14528, 26274, 47012, 83787, 149619, 268568, 484722, 878014, 1592150, 2884434, 5215660, 9413514, 16970286, 30584282, 55140634, 99481417, 179592631, 324338478, 585786560

Offset

1,1

Comments

Column 5 of A217883.

Links

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

Formula

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

Empirical g.f.: x*(1 + x^2 + x^3 + x^4 + x^5)*(3 + x^2 + x^3 + x^4 + x^5) / ((1 - x + x^3 + x^4 + x^5)*(1 - 2*x + x^2 - x^3 - x^6)). - Colin Barker, Jul 23 2018

Example

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

Crossrefs

Cf. A217883.

Sequence in context: A223718 A217882 A217881 * A217879 A217878 A192389

Adjacent sequences: A217877 A217878 A217879 * A217881 A217882 A217883

Keyword

nonn

Author

R. H. Hardin, Oct 14 2012

Status

approved