A231524 Number of 2 X n 0..1 arrays with no element less than a strict majority of its horizontal, diagonal and antidiagonal neighbors.

4, 10, 34, 107, 342, 1069, 3381, 10689, 33808, 106804, 337525, 1066772, 3371763, 10656541, 33680325, 106448622, 336438736, 1063336915, 3360744286, 10621851017, 33571065345, 106103576857, 335347363656, 1059887498352, 3349844553061

Offset

1,1

Links

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

Formula

Empirical: a(n) = 4*a(n-1) - 3*a(n-2) + a(n-3) + 6*a(n-4) - 18*a(n-5).

Empirical g.f.: x*(4 - 6*x + 6*x^2 - 3*x^3 - 18*x^4) / (1 - 4*x + 3*x^2 - x^3 - 6*x^4 + 18*x^5). - Colin Barker, Sep 29 2018

Example

Some solutions for n=7:
  0 1 0 0 0 0 1      1 0 0 0 0 0 1      0 0 0 1 0 0 0
  1 0 0 1 0 1 1      1 0 0 1 0 0 1      0 0 1 0 0 1 0

Crossrefs

Row 2 of A231523.

Sequence in context: A223006 A156700 A274479 * A182645 A006343 A149173

Adjacent sequences: A231521 A231522 A231523 * A231525 A231526 A231527

Keyword

nonn

Author

R. H. Hardin, Nov 10 2013

Status

approved