A203818 Number of (n+1) X (n+1) 0..3 arrays with no 2 X 2 subblock having equal diagonal elements or equal antidiagonal elements.

144, 27216, 28005264, 157025515248, 4802315365587600, 801390350388172407408, 729769248139791415275682704, 3626511808446899710619902249927536

Offset

1,1

Comments

Diagonal of A203826.

Links

Table of n, a(n) for n=1..8.

Example

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

Crossrefs

Cf. A203826.

Sequence in context: A304555 A362547 A231784 * A299953 A230788 A231938

Adjacent sequences: A203815 A203816 A203817 * A203819 A203820 A203821

Keyword

nonn

Author

R. H. Hardin, Jan 06 2012

Status

approved