login
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.
1
33, 2399, 252097, 29452071, 3532758473, 426525918799, 51580839266577, 6240392439847991, 755059969459250713, 91361403922865509599, 11054703458723757804257, 1337618299713909786621511
OFFSET
1,1
LINKS
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
KEYWORD
nonn
AUTHOR
R. H. Hardin, Oct 29 2015
STATUS
approved