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A256728 Number of (n+2) X (1+2) 0..1 arrays with no 3 x 3 subblock diagonal sum zero and no antidiagonal sum three. 1
384, 2304, 13056, 73984, 413440, 2310400, 12865280, 71639296, 398552832, 2217279744, 12332535552, 68593705216, 381495652096, 2121753477376, 11800309124864, 65628404490496, 364996358434560, 2029949420601600 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
FORMULA
Empirical: a(n) = 7*a(n-1) - 56*a(n-3) + 64*a(n-4).
Empirical g.f.: 128*x*(3 - 3*x - 24*x^2 + 32*x^3) / ((1 - 7*x + 8*x^2)*(1 - 8*x^2)). - Colin Barker, Dec 20 2018
EXAMPLE
Some solutions for n=4:
..1..0..1....1..0..0....1..0..1....1..1..0....0..1..0....0..0..0....1..1..0
..0..1..0....0..0..1....1..0..0....1..1..1....0..1..0....1..1..1....1..1..0
..0..0..1....1..1..0....0..1..0....1..0..1....1..0..0....0..1..0....0..0..0
..1..1..1....0..0..0....1..0..1....1..0..0....0..0..1....0..1..0....1..1..0
..0..0..0....1..0..0....1..1..1....0..1..0....0..1..0....0..0..1....0..0..1
..1..1..1....1..0..1....0..0..1....0..0..0....0..0..1....0..1..1....1..1..0
CROSSREFS
Column 1 of A256735.
Sequence in context: A134175 A233886 A256735 * A236029 A252904 A252899
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 09 2015
STATUS
approved

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Last modified February 22 20:29 EST 2024. Contains 370264 sequences. (Running on oeis4.)