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A209984
Number of 2 X 2 matrices having all elements in {-n,...n} and determinant 2.
4
0, 4, 92, 156, 284, 412, 604, 796, 1052, 1244, 1628, 1948, 2204, 2588, 3164, 3420, 3932, 4444, 5020, 5596, 6108, 6492, 7452, 8156, 8668, 9308, 10460, 11036, 11804, 12700, 13468, 14428, 15452, 16092, 17628, 18396, 19164, 20316, 22044
OFFSET
0,2
COMMENTS
See A210000 for a guide to related sequences.
EXAMPLE
a(1) counts these matrices (in reduced notation):
(-1,-1,1,-1), (-1,1,-1,-1), (1,-1,1,1), (1,1,-1,1)
MATHEMATICA
(See the Mathematica section at A209981.)
CROSSREFS
Cf. A210000.
Sequence in context: A337827 A129434 A248041 * A113252 A003737 A362511
KEYWORD
nonn
AUTHOR
Clark Kimberling, Mar 17 2012
STATUS
approved