A263908 Number of (2n+1) X (3+2) 0..1 arrays with each row and column modulo 3 equal to 1, read as a binary number with top and left being the most significant bits.

33, 2399, 252097, 29452071, 3532758473, 426525918799, 51580839266577, 6240392439847991, 755059969459250713, 91361403922865509599, 11054703458723757804257, 1337618299713909786621511

Offset

1,1

Links

R. H. Hardin, Table of n, a(n) for n = 1..105

Formula

Empirical: a(n) = 169*a(n-1) - 6387*a(n-2) + 71671*a(n-3) - 195052*a(n-4).

Conjectures from Colin Barker, Jan 03 2019: (Start)

G.f.: x*(33 - 3178*x + 57437*x^2 - 195052*x^3) / ((1 - 4*x)*(1 - 13*x)*(1 - 31*x)*(1 - 121*x)).

a(n) = (5*2^(1+2*n) + 11^(1+2*n) + 31*13^n + 29*31^n) / 81.

(End)

Example

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

Crossrefs

Column 3 of A263913 (nonzero terms).

Sequence in context: A294954 A372903 A118641 * A358808 A111922 A136541

Adjacent sequences: A263905 A263906 A263907 * A263909 A263910 A263911

Keyword

nonn

Author

R. H. Hardin, Oct 29 2015

Status

approved