A232131 Number of (n+1) X (2+1) 0..2 arrays with no element equal to a strict majority of its horizontal and antidiagonal neighbors, with values 0..2 introduced in row major order.

36, 728, 14752, 298912, 6056640, 122721280, 2486611712, 50384397824, 1020902270976, 20685797427200, 419141212008448, 8492752393142272, 172082441775661056, 3486780892303556608, 70650095765044723712

Offset

1,1

Links

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

Formula

Empirical: a(n) = 22*a(n-1) - 36*a(n-2) + 16*a(n-3).

Empirical g.f.: 4*x*(9 - 16*x + 8*x^2) / (1 - 22*x + 36*x^2 - 16*x^3). - Colin Barker, Oct 03 2018

Example

Some solutions for n=4:
..0..1..0....0..1..0....0..1..0....0..1..0....0..1..0....0..1..0....0..1..0
..1..0..0....0..1..0....1..0..2....0..0..2....0..1..0....0..1..1....1..0..1
..1..2..1....1..2..0....0..1..0....2..2..1....0..0..2....1..0..0....2..1..2
..0..1..2....0..2..0....2..0..1....0..2..1....1..2..1....1..2..2....0..0..1
..2..0..2....2..1..0....0..1..2....1..0..1....0..1..0....1..0..2....1..0..2

Crossrefs

Column 2 of A232137.

Sequence in context: A185491 A220758 A054339 * A138832 A223998 A109405

Adjacent sequences: A232128 A232129 A232130 * A232132 A232133 A232134

Keyword

nonn

Author

R. H. Hardin, Nov 19 2013

Status

approved