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A258675 Number of (n+2) X (2+2) 0..1 arrays with no 3 x 3 subblock diagonal sum equal to the antidiagonal sum. 1
1600, 10000, 67600, 456976, 2944656, 18974736, 125888400, 835210000, 5443488400, 35477982736, 233749042576, 1540071072016, 10079990010000, 65975006250000, 433559848410000, 2849172024948496, 18677605395953296, 122440112521198096 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
FORMULA
Empirical: a(n) = 9*a(n-1) - 36*a(n-2) + 180*a(n-3) - 2880*a(n-5) + 9216*a(n-6) - 36864*a(n-7) + 65536*a(n-8).
Empirical g.f.: 16*x*(100 - 275*x + 2200*x^2 - 4964*x^3 - 33408*x^4 + 85248*x^5 - 442368*x^6 + 1048576*x^7) / ((1 - 4*x)*(1 + 4*x)*(1 - 9*x + 16*x^2)*(1 + 36*x^2 + 256*x^4)). - Colin Barker, Dec 22 2018
EXAMPLE
Some solutions for n=3:
..1..1..1..1....1..0..1..1....0..1..0..1....1..1..1..1....0..0..0..0
..1..0..0..0....0..1..1..0....1..0..0..0....1..0..1..0....1..0..1..1
..0..0..1..1....0..1..1..0....0..1..1..0....1..0..0..1....1..0..0..1
..0..0..0..1....1..0..0..0....0..1..0..0....1..0..0..1....1..0..0..0
..1..0..1..0....0..0..0..0....1..1..1..1....0..1..1..1....0..1..1..0
CROSSREFS
Column 2 of A258681.
Sequence in context: A309562 A043412 A202096 * A236992 A251969 A206250
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jun 07 2015
STATUS
approved

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Last modified June 12 19:52 EDT 2024. Contains 373360 sequences. (Running on oeis4.)