A255094 Number of (n+2) X (1+2) 0..1 arrays with no 3 x 3 subblock diagonal sum 1 and no antidiagonal sum 1 and no row sum 1 and no column sum 1.

36, 77, 179, 419, 991, 2345, 5537, 13105, 31063, 73591, 174311, 412949, 978301, 2317617, 5490567, 13007447, 30815207, 73002717, 172947085, 409720065, 970646871, 2299510047, 5447651751, 12905753661, 30574362581, 72432161761

Offset

1,1

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = 2*a(n-1) - a(n-2) + 5*a(n-3) - 2*a(n-4) + 3*a(n-5) - 2*a(n-6) - 2*a(n-7) - 2*a(n-8) - 2*a(n-9) + 2*a(n-11) for n>12.

Empirical g.f.: x*(36 + 5*x + 61*x^2 - 42*x^3 + 19*x^4 - 67*x^5 - 58*x^6 - 52*x^7 - 26*x^8 + 24*x^9 + 38*x^10 - 2*x^11) / ((1 - x)*(1 - x - 5*x^3 - 3*x^4 - 6*x^5 - 4*x^6 - 2*x^7 + 2*x^9 + 2*x^10)). - Colin Barker, Dec 18 2018

Example

Some solutions for n=4:
..1..1..1....0..1..1....1..1..1....1..1..0....1..1..1....1..0..1....1..1..0
..1..1..1....1..1..1....1..1..1....1..1..1....1..1..1....1..1..1....0..1..1
..1..1..1....1..0..1....0..0..0....1..1..1....1..0..1....1..1..1....1..1..1
..0..1..1....1..1..1....1..1..1....1..1..1....1..1..1....1..1..1....1..1..1
..1..1..1....1..1..0....1..1..1....1..1..1....1..1..0....1..0..1....0..1..1
..1..0..1....1..0..1....1..1..0....0..1..1....1..0..1....1..1..1....1..1..1

Crossrefs

Column 1 of A255101.

Sequence in context: A319602 A262796 A255101 * A261284 A111163 A286430

Adjacent sequences: A255091 A255092 A255093 * A255095 A255096 A255097

Keyword

nonn

Author

R. H. Hardin, Feb 14 2015

Status

approved