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A053171
Number of 3 X 3 integer matrices with elements in the range [ -n,n ] which represent a rotation of order 2.
5
81, 321, 825, 1689, 2601, 4185, 5529, 8145, 10401, 13137
OFFSET
1,1
FORMULA
A053170(n) = 2 * (1 + a(n) + A053172(n) + A053173(n) + A053174(n)).
CROSSREFS
KEYWORD
nonn,more
AUTHOR
STATUS
approved