A205155 Number of n X n 0..3 arrays with no occurrence of three equal elements in a row horizontally, vertically or nw-to-se diagonally, and new values 0..3 introduced in row major order.
1, 15, 6941, 54314298, 4826926610498, 4948963310952700521
Offset: 1
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Examples
Some solutions for n=5 ..0..0..1..0..0....0..0..1..0..1....0..0..1..0..0....0..1..0..0..1 ..2..1..3..2..2....0..2..2..1..0....1..1..2..3..3....1..1..2..2..3 ..2..2..3..2..2....3..1..0..1..0....3..2..0..0..2....3..0..3..3..0 ..3..1..1..3..1....0..0..1..2..1....1..1..3..1..0....0..3..3..0..2 ..1..2..1..3..2....3..3..0..2..0....0..1..0..2..3....1..0..1..0..1
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