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A222821 T(n,k)=Number of idempotent n X n 0..k matrices 3
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 (list; table; graph; refs; listen; history; text; internal format)
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 * A245497 A086328 A095997

Adjacent sequences:  A222818 A222819 A222820 * A222822 A222823 A222824

KEYWORD

nonn,tabl

AUTHOR

R. H. Hardin Apr 09 2013

STATUS

approved

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Last modified November 14 22:32 EST 2019. Contains 329134 sequences. (Running on oeis4.)