A268052 Number of n X 4 0..2 arrays with new values introduced in each row and column in sequential order starting with zero.

1, 8, 86, 1082, 14554, 200818, 2796826, 39082562, 546791114, 7653252338, 107136417466, 1499864270242, 20997871916074, 293969067496658, 4115561248327706, 57617828993493122, 806649463493495434

Offset

1,2

Links

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

Formula

Empirical: a(n) = 21*a(n-1) - 108*a(n-2) + 140*a(n-3).

Conjectures from Colin Barker, Jan 11 2019: (Start)

G.f.: x*(1 - 13*x + 26*x^2) / ((1 - 2*x)*(1 - 5*x)*(1 - 14*x)).

a(n) = (105*2^n + 196*5^n + 25*2^(1+n)*7^n) / 1890.

(End)

Example

Some solutions for n=4:
..0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0
..0..1..0..1....0..1..1..0....0..0..1..1....0..1..1..1....0..1..0..1
..0..0..1..1....0..1..2..1....0..0..0..0....0..1..1..2....0..0..1..2
..0..1..0..0....0..1..0..1....0..1..1..0....0..1..0..1....0..1..1..1

Crossrefs

Column 4 of A268056.

Sequence in context: A357420 A371407 A369505 * A268075 A202545 A131812

Adjacent sequences: A268049 A268050 A268051 * A268053 A268054 A268055

Keyword

nonn

Author

R. H. Hardin, Jan 25 2016

Status

approved