A224117 Number of idempotent n X n 0..1 matrices of rank n-2

0, 1, 27, 282, 2050, 12405, 67557, 344708, 1686132, 8017335, 37383775, 171917790, 782635542, 3535573769, 15875062665, 70921483080, 315457366696

Offset

1,3

Comments

Column 1 of A224118

Links

Table of n, a(n) for n=1..17.

Example

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

Crossrefs

Sequence in context: A042412 A078876 A059603 * A251080 A049011 A115246

Adjacent sequences: A224114 A224115 A224116 * A224118 A224119 A224120

Keyword

nonn

Author

R. H. Hardin Apr 09 2013

Status

approved