A203872 Number of (n+1)X3 0..3 arrays with no 2X2 subblock having equal diagonal elements or equal antidiagonal elements, and new values 0..3 introduced in row major order

55, 1135, 23815, 500095, 10501975, 220541455, 4631370535, 97258781215, 2042434405495, 42891122515375, 900713572822855, 18914985029279935, 397214685614878615, 8341508397912450895, 175171676356161468775

Offset

1,1

Comments

Column 2 of A203878

Links

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

Formula

Empirical: a(n) = 54*21^(n-1) +1

Example

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

Crossrefs

Sequence in context: A008402 A281073 A329753 * A297753 A134291 A157096

Adjacent sequences: A203869 A203870 A203871 * A203873 A203874 A203875

Keyword

nonn

Author

R. H. Hardin Jan 07 2012

Status

approved