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A281856
One fourth of the order of the abelian non-cyclic groups (Z/A033949(n)*Z)^x.
2
1, 1, 2, 2, 2, 3, 2, 3, 2, 4, 5, 6, 3, 6, 4, 3, 5, 6, 4, 8, 6, 10, 6, 9, 4, 9, 8, 12, 5, 8, 11, 6, 6, 10, 9, 15, 6, 8, 6, 16, 14, 10, 6, 18, 11, 15, 18, 8, 15, 10, 8, 12, 12, 9, 10, 18, 12, 9, 22, 14, 18, 24, 8, 20
OFFSET
1,3
COMMENTS
a(n) is one fourth of the row product of the irregular triangle A281854.
FORMULA
a(n) = A000010(A033949(n))/4, n >= 1.
MATHEMATICA
EulerPhi@ Select[Range[2, 130], ! IntegerQ@ PrimitiveRoot@ # &]/4 (* Michael De Vlieger, Feb 02 2017 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Wolfdieter Lang, Feb 02 2017
STATUS
approved