A223450 T(n,k)=Number of idempotent n X n -k..k matrices of rank n-1

1, 1, 10, 1, 26, 75, 1, 42, 399, 500, 1, 58, 927, 5220, 3125, 1, 74, 1815, 17380, 64285, 18750, 1, 106, 2751, 46884

Offset

1,3

Comments

Table starts

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

....10....26....42....58...74.106

....75...399...927..1815.2751

...500..5220.17380.46884

..3125.64285

.18750

Links

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

Example

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

Crossrefs

Sequence in context: A013617 A243002 A050999 * A221311 A361949 A070246

Adjacent sequences: A223447 A223448 A223449 * A223451 A223452 A223453

Keyword

nonn,tabl

Author

R. H. Hardin Apr 09 2013

Status

approved