A224114 T(n,k) = Number of idempotent n X n 0..k matrices of rank 2.

0, 0, 1, 0, 1, 21, 0, 1, 51, 282, 0, 1, 93, 1434, 3070, 0, 1, 147, 4182, 30410, 29505, 0, 1, 213, 9762, 136990, 546465, 260967, 0, 1, 291, 19110, 467290, 3784335, 8815317, 2175236, 0, 1, 381, 34602, 1240310, 18925485, 94529631

Offset

1,6

Comments

Table starts:

.......0.......0........0........0.......0.....0...0.0.0

.......1.......1........1........1.......1.....1...1.1

......21......51.......93......147.....213...291.381

.....282....1434.....4182.....9762...19110.34602

....3070...30410...136990...467290.1240310

...29505..546465..3784335.18925485

..260967.8815317.94529631

.2175236

Links

Table of n, a(n) for n=1..43.

Example

Some solutions for n=3, k=4:
..1..0..2....0..1..3....0..0..1....0..0..0....0..0..0....1..0..0....1..3..0
..0..1..3....0..1..0....0..1..0....3..1..0....0..1..0....0..1..1....0..0..0
..0..0..0....0..0..1....0..0..1....3..0..1....4..0..1....0..0..0....0..3..1

Crossrefs

Row 3 is A224334.

Sequence in context: A209614 A167263 A324685 * A110454 A265156 A040445

Adjacent sequences: A224111 A224112 A224113 * A224115 A224116 A224117

Keyword

nonn,tabl,more

Author

R. H. Hardin, Apr 09 2013

Status

approved