A202330 Number of (n+1) X 4 binary arrays with consecutive windows of two bits considered as a binary number nondecreasing in every row and column.

36, 82, 162, 289, 478, 746, 1112, 1597, 2224, 3018, 4006, 5217, 6682, 8434, 10508, 12941, 15772, 19042, 22794, 27073, 31926, 37402, 43552, 50429, 58088, 66586, 75982, 86337, 97714, 110178, 123796, 138637, 154772, 172274, 191218, 211681, 233742

Offset

1,1

Comments

Column 3 of A202335.

Links

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

Formula

Empirical: a(n) = (1/12)*n^4 + (4/3)*n^3 + (83/12)*n^2 + (44/3)*n + 13.

Conjectures from Colin Barker, May 27 2018: (Start)

G.f.: x*(36 - 98*x + 112*x^2 - 61*x^3 + 13*x^4) / (1 - x)^5.

a(n) = 5*a(n-1) - 10*a(n-2) + 10*a(n-3) - 5*a(n-4) + a(n-5).

(End)

Example

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

Crossrefs

Cf. A202335.

Sequence in context: A341555 A084006 A254648 * A226264 A243804 A043183

Adjacent sequences: A202327 A202328 A202329 * A202331 A202332 A202333

Keyword

nonn

Author

R. H. Hardin, Dec 17 2011

Status

approved