A222823 Number of idempotent 4X4 0..n matrices.

452, 2052, 5584, 12476, 23568, 41668, 67136, 104112, 153604, 219728, 303468, 412720, 545012, 709272, 907828, 1146704, 1426212, 1759348, 2142176, 2590236, 3101848, 3686444, 4346808, 5102188, 5942936

Offset: 1

Author

R. H. Hardin Apr 09 2013

Keywords

• nonn

Comments

Row 4 of A222821

Examples

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