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

1,1

Comments

Row 4 of A222821

Links

Table of n, a(n) for n=1..25.

Example

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

Crossrefs

Sequence in context: A224561 A116308 A183636 * A205209 A236665 A318627

Adjacent sequences: A222820 A222821 A222822 * A222824 A222825 A222826

Keyword

nonn

Author

R. H. Hardin Apr 09 2013

Status

approved