A232043 Number of n X 4 0..1 arrays with no element less than a strict majority of its horizontal and antidiagonal neighbors.

7, 34, 318, 3082, 29974, 290672, 2821630, 27382537, 265752221, 2579134666, 25030650682, 242923857095, 2357589444796, 22880536455569, 222056873956095, 2155074272108794, 20915115264627031, 202982352989424279

Offset

1,1

Links

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

Formula

Empirical: a(n) = 7*a(n-1) + 29*a(n-2) - 15*a(n-3) - 116*a(n-4) + 17*a(n-5) + 99*a(n-6) + 12*a(n-7) - 16*a(n-8) for n>9.

Empirical g.f.: x*(7 - 15*x - 123*x^2 - 25*x^3 + 500*x^4 + 71*x^5 - 473*x^6 - 95*x^7 + 84*x^8) / (1 - 7*x - 29*x^2 + 15*x^3 + 116*x^4 - 17*x^5 - 99*x^6 - 12*x^7 + 16*x^8). - Colin Barker, Oct 02 2018

Example

Some solutions for n=6:
..0..0..0..0....0..0..1..0....0..0..0..0....0..0..0..1....0..0..0..1
..0..1..0..1....0..0..0..0....0..1..1..0....0..0..0..1....0..0..0..1
..0..0..1..0....0..1..0..1....0..0..0..1....1..0..0..1....0..0..0..0
..0..0..0..0....1..0..0..0....0..1..1..0....0..0..0..0....0..0..0..0
..1..0..1..1....0..0..0..0....0..0..0..0....0..0..1..0....1..1..0..0
..0..0..0..0....1..1..0..0....1..1..1..1....1..1..0..0....1..0..0..1

Crossrefs

Column 4 of A232047.

Sequence in context: A273221 A144038 A027842 * A360506 A027683 A196968

Adjacent sequences: A232040 A232041 A232042 * A232044 A232045 A232046

Keyword

nonn

Author

R. H. Hardin, Nov 17 2013

Status

approved