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A073312 Number of nonsquarefree numbers in the reduced residue system of n. 2
0, 0, 0, 0, 1, 0, 1, 0, 2, 1, 3, 0, 4, 1, 2, 1, 5, 0, 6, 1, 4, 1, 7, 0, 7, 2, 5, 3, 11, 0, 11, 3, 7, 3, 9, 1, 13, 3, 7, 2, 14, 1, 14, 3, 6, 4, 16, 1, 16, 3, 11, 5, 20, 2, 15, 4, 13, 5, 22, 1, 23, 5, 10, 6, 18, 2, 25, 6, 15, 2, 26, 2, 27, 6, 11, 7, 24, 2, 29, 4, 17, 8, 31, 1, 23, 8, 17, 8, 33, 1, 28 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,9

COMMENTS

a(n) + A073311(n) = A000010(n).

LINKS

Table of n, a(n) for n=1..91.

EXAMPLE

n=15, there are A000010(15)=8 residues: 1, 2, 4=2^2, 7, 8=2^3, 11, 13 and 14; two of them are not squarefree: 4 and 8, therefore a(15)=2.

CROSSREFS

Cf. A073311, A013929, A000010, A048864, A048865.

Sequence in context: A262677 A307742 A297109 * A166514 A246024 A278529

Adjacent sequences:  A073309 A073310 A073311 * A073313 A073314 A073315

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller, Jul 25 2002

STATUS

approved

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Last modified October 18 17:13 EDT 2019. Contains 328186 sequences. (Running on oeis4.)