A222821 T(n,k)=Number of idempotent n X n 0..k matrices

2, 2, 8, 2, 12, 50, 2, 16, 122, 452, 2, 20, 218, 2052, 5682, 2, 24, 344, 5584, 54182, 96608, 2, 28, 488, 12476, 248442, 2236302, 2185738, 2, 32, 668, 23568, 855192, 20394466, 145121216, 65108492, 2, 36, 860, 41668, 2319872, 126252320

Offset

1,1

Comments

Table starts

........2.........2........2.........2.......2.....2...2..2.2

........8........12.......16........20......24....28..32.36

.......50.......122......218.......344.....488...668.860

......452......2052.....5584.....12476...23568.41668

.....5682.....54182...248442....855192.2319872

....96608...2236302.20394466.126252320

..2185738.145121216

.65108492

Links

Table of n, a(n) for n=1..42.

Example

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

Crossrefs

Sequence in context: A092694 A098984 A088560 * A363418 A245497 A086328

Adjacent sequences: A222818 A222819 A222820 * A222822 A222823 A222824

Keyword

nonn,tabl

Author

R. H. Hardin Apr 09 2013

Status

approved