A219129 Number of 2 X n arrays of the minimum value of corresponding elements and their horizontal, diagonal or antidiagonal neighbors in a random 0..2 2 X n array.

9, 15, 87, 205, 899, 2521, 9709, 29747, 107261, 344055, 1199763, 3940341, 13507819, 44905025, 152598957, 510467683, 1726955485, 5795447559, 19561570195, 65753998917, 221680877531, 745782497713, 2512791313869, 8457223721011

Offset

1,1

Comments

Row 2 of A219128.

Links

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

Formula

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

Empirical g.f.: x*(9 - 3*x + 3*x^2 - 5*x^3 - 6*x^4 - 10*x^6 - 4*x^7) / (1 - 2*x - 6*x^2 + 6*x^3 - 7*x^4 + 10*x^5 - 6*x^6 + 6*x^7 + 4*x^8). - Colin Barker, Jul 25 2018

Example

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

Crossrefs

Cf. A219128.

Sequence in context: A037378 A100663 A304457 * A226927 A152219 A173037

Adjacent sequences: A219126 A219127 A219128 * A219130 A219131 A219132

Keyword

nonn

Author

R. H. Hardin, Nov 12 2012

Status

approved