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A223454
Number of idempotent 2 X 2 -n..n matrices.
2
12, 28, 44, 60, 76, 108, 124, 140, 156, 188, 204, 236, 252, 284, 316, 332, 348, 380, 396, 428, 460, 492, 508, 540, 556, 588, 604, 636, 652, 716, 732, 748, 780, 812, 844, 876, 892, 924, 956, 988, 1004, 1068, 1084, 1116, 1148, 1180, 1196, 1228, 1244, 1276, 1308, 1340
OFFSET
1,1
COMMENTS
Row 2 of A223453.
LINKS
EXAMPLE
Some solutions for n=3
..0..0....0..0....1.-3....3.-3...-2.-3....1..0....0.-3...-2..3....1..0...-1.-2
.-1..1...-2..1....0..0....2.-2....2..3...-3..0....0..1...-2..3....1..0....1..2
CROSSREFS
Cf. A223453.
Sequence in context: A044454 A098502 A158953 * A107707 A183053 A126195
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 09 2013
STATUS
approved