A203820 Number of (n+1)X3 0..3 arrays with no 2X2 subblock having equal diagonal elements or equal antidiagonal elements

1296, 27216, 571536, 12002256, 252047376, 5292994896, 111152892816, 2334210749136, 49018425731856, 1029386940368976, 21617125747748496, 453959640702718416, 9533152454757086736, 200196201549898821456

Offset

1,1

Comments

Column 2 of A203826

Links

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

Formula

Empirical: a(n) = 1296*21^(n-1)

Example

Some solutions for n=4
..1..0..1....3..1..3....2..1..1....1..0..0....0..2..0....3..0..1....2..0..1
..2..2..1....2..0..3....2..3..2....1..3..1....3..1..0....1..2..1....1..3..1
..0..0..1....1..1..1....0..0..0....2..2..0....2..1..2....1..2..3....0..2..1
..1..2..1....3..2..3....2..1..3....1..3..1....0..3..2....3..0..3....1..2..3
..1..0..0....0..1..1....2..0..2....0..2..1....0..1..0....1..1..3....0..2..3

Crossrefs

Sequence in context: A223560 A016912 A330980 * A017056 A223596 A265471

Adjacent sequences: A203817 A203818 A203819 * A203821 A203822 A203823

Keyword

nonn

Author

R. H. Hardin Jan 06 2012

Status

approved