A202457 Number of (n+2) X 6 binary arrays with consecutive windows of three bits considered as a binary number nondecreasing in every row and column.

1331, 2835, 5735, 10918, 19614, 33468, 54618, 85779, 130333, 192425, 277065, 390236, 539008, 731658, 977796, 1288497, 1676439, 2156047, 2743643, 3457602, 4318514, 5349352, 6575646, 8025663, 9730593, 11724741, 14045725, 16734680

Offset

1,1

Comments

Column 4 of A202461.

Links

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

Formula

Empirical: a(n) = (1/120)*n^6 + (17/40)*n^5 + (27/4)*n^4 + (1195/24)*n^3 + (22769/120)*n^2 + (28277/60)*n + 613.

Conjectures from Colin Barker, May 31 2018: (Start)

G.f.: x*(1331 - 6482*x + 13841*x^2 - 16277*x^3 + 10983*x^4 - 4003*x^5 + 613*x^6) / (1 - x)^7.

a(n) = 7*a(n-1) - 21*a(n-2) + 35*a(n-3) - 35*a(n-4) + 21*a(n-5) - 7*a(n-6) + a(n-7) for n>7.

(End)

Example

Some solutions for n=5:
..0..0..0..0..0..0....0..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..0..0..1..0....0..0..0..0..0..0....0..0..0..1..0..0
..0..0..0..0..0..0....0..0..0..0..1..1....0..0..0..0..1..0....0..0..0..1..0..0
..0..0..0..0..0..0....0..0..0..0..1..1....0..0..0..0..1..0....0..0..0..1..1..0
..0..0..0..1..0..1....0..0..0..0..1..1....0..0..0..1..1..0....0..0..0..1..1..1
..0..0..0..0..1..0....0..0..0..0..1..1....0..0..0..1..1..0....0..0..0..1..1..1
..0..0..1..1..1..1....0..1..1..1..1..1....0..0..0..0..1..0....0..0..1..1..1..1

Crossrefs

Cf. A202461.

Sequence in context: A182371 A252258 A038677 * A252347 A295900 A030100

Adjacent sequences: A202454 A202455 A202456 * A202458 A202459 A202460

Keyword

nonn

Author

R. H. Hardin, Dec 19 2011

Status

approved