VOOZH about

URL: https://oeis.org/A258959

⇱ A258959 - OEIS

login
A258959
Number of (n+2) X (1+2) 0..1 arrays with no 3 X 3 subblock diagonal sum 0 and no antidiagonal sum 3 and no row sum 0 or 3 and no column sum 0 or 3.
1
66, 158, 214, 462, 676, 1374, 2040, 4104, 6136, 12296, 18424, 36872, 55288, 110600, 165880, 331784, 497656, 995336, 1492984, 2985992, 4478968, 8957960, 13436920, 26873864, 40310776, 80621576, 120932344, 241864712, 362797048, 725594120
OFFSET
1,1
LINKS
FORMULA
Empirical: a(n) = -a(n-1) + 3*a(n-2) + 3*a(n-3) for n>9.
Empirical g.f.: 2*x*(33 + 112*x + 87*x^2 + 2*x^3 + 11*x^4 + 11*x^5 - 3*x^7 - x^8) / ((1 + x)*(1 - 3*x^2)). - Colin Barker, Dec 23 2018
EXAMPLE
Some solutions for n=4:
..1..1..0....1..0..1....0..0..1....0..0..1....1..0..1....0..1..1....0..1..0
..1..0..0....1..1..0....1..0..0....1..1..0....1..1..0....1..0..0....1..0..1
..0..1..1....0..0..1....0..1..1....0..1..0....0..1..0....0..0..1....1..0..1
..1..0..0....1..0..0....1..0..0....1..0..1....1..0..1....1..1..0....0..1..0
..0..1..1....0..1..1....0..1..1....0..0..1....1..0..1....0..1..0....0..1..1
..0..0..1....1..0..0....0..1..1....0..1..0....0..1..0....0..0..1....1..0..0
CROSSREFS
Column 1 of A258966.
Sequence in context: A278783 A358102 A258966 * A062035 A043514 A044398
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jun 15 2015
STATUS
approved