A217882 Number of n element 0..2 arrays with each element the minimum of 7 adjacent elements of a random 0..2 array of n+6 elements.

3, 9, 22, 46, 86, 148, 239, 367, 546, 806, 1212, 1896, 3107, 5285, 9166, 15926, 27386, 46326, 77008, 126100, 204345, 329557, 531883, 862787, 1409973, 2321625, 3845207, 6389207, 10621657, 17628795, 29173804, 48123884, 79161386, 129972892

Offset: 1

Author

R. H. Hardin, Oct 14 2012

Keywords

• nonn

Comments

Column 7 of A217883.

Examples

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

Links

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

Crossrefs

Cf. A217883.

Formula

Empirical: a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3) + 3*a(n-8) - a(n-9) + a(n-10) + a(n-11) + a(n-12) + a(n-13) + a(n-14) + a(n-15).

Empirical g.f.: x*(1 + x^2 + x^3 + x^4 + x^5 + x^6 + x^7)*(3 + x^2 + x^3 + x^4 + x^5 + x^6 + x^7) / ((1 - x + x^4 + x^5 + x^6 + x^7)*(1 - 2*x + x^2 - x^4 - x^8)). - Colin Barker, Jul 23 2018