A217978 Number of n X 4 arrays of the minimum value of corresponding elements and their horizontal, vertical, diagonal or antidiagonal neighbors in a random 0..1 n X 4 array.

6, 6, 36, 98, 362, 1180, 4046, 13594, 46052, 155494, 525730, 1776548, 6004634, 20293538, 68587432, 231806206, 783444274, 2647830256, 8948960354, 30245088582, 102220312680, 345477304222, 1167620873294, 3946246173440, 13337256366382

Offset

1,1

Comments

Column 4 of A217982.

Links

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

Formula

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

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

Example

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

Crossrefs

Cf. A217982.

Sequence in context: A245131 A038260 A242087 * A257626 A222340 A215270

Adjacent sequences: A217975 A217976 A217977 * A217979 A217980 A217981

Keyword

nonn

Author

R. H. Hardin, Oct 16 2012

Status

approved