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A221311 T(n,k)=Number of idempotent n X n -k..k matrices of rank 1 1
1, 1, 10, 1, 26, 87, 1, 42, 447, 740, 1, 58, 999, 6820, 6285, 1, 74, 1935, 20708 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

Table starts

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

...10...26....42...58.74

...87..447...999.1935

..740.6820.20708

.6285

LINKS

Table of n, a(n) for n=1..19.

EXAMPLE

Some solutions for n=3 k=4

..0.-3.-4....2.-1..1....4..4.-4....0..0..4...-2..3..4....1..2..2...-4.-4.-1

..0.-3.-4....0..0..0...-4.-4..4....0..0.-4...-2..3..4...-2.-4.-4....4..4..1

..0..3..4...-2..1.-1...-1.-1..1....0..0..1....0..0..0....2..4..4....4..4..1

CROSSREFS

Row 2 is A223451

Sequence in context: A243002 A050999 A223450 * A070246 A085044 A215268

Adjacent sequences:  A221308 A221309 A221310 * A221312 A221313 A221314

KEYWORD

nonn,tabl

AUTHOR

R. H. Hardin Apr 10 2013

STATUS

approved

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Last modified January 29 08:12 EST 2020. Contains 331337 sequences. (Running on oeis4.)