

A239039


Number of n X n 0..3 arrays with no element equal to one plus the sum of elements to its left or one plus the sum of the elements above it, modulo 4


0




OFFSET

1,1


COMMENTS



LINKS



EXAMPLE

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


CROSSREFS



KEYWORD

nonn


AUTHOR



STATUS

approved



