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

Author

R. H. Hardin, Dec 17 2011

Keywords

• nonn

Comments

Column 3 of A202335.

Examples

			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
		

Links

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

Crossrefs

Cf. A202335.

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)