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A058979 Number of m such that phi(m) = 4n. 0
4, 5, 6, 6, 5, 10, 2, 7, 8, 9, 3, 11, 2, 3, 9, 8, 0, 17, 0, 10, 6, 6, 3, 17, 4, 3, 9, 6, 3, 17, 0, 9, 7, 2, 3, 21, 2, 0, 7, 12, 3, 12, 2, 8, 10, 4, 0, 21, 2, 8, 3, 4, 3, 19, 5, 8, 2, 6, 0, 31, 0, 0, 9, 10, 3, 10, 2, 5, 9, 8, 0, 28, 2, 3, 5, 0, 0, 16, 2, 16, 8, 4, 3, 18, 0, 3, 6, 12, 3, 25, 0, 5, 2, 0 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

COMMENTS

Size of invphi(4n) solution-set.

LINKS

Table of n, a(n) for n=0..93.

EXAMPLE

4n=48: invphi(48) has 11 solutions: {65,104,105,112,130,140,144,156,168,180,210} The value of the "nops(invphi(4k))" number seems to take any integer except 1.

MAPLE

with(numtheory): [seq(nops(invphi(4*k)), k=1...256)];

CROSSREFS

A000010, A005277.

Sequence in context: A112780 A021223 A206291 * A225491 A046343 A022911

Adjacent sequences:  A058976 A058977 A058978 * A058980 A058981 A058982

KEYWORD

nonn

AUTHOR

Labos Elemer, Jan 15 2001

STATUS

approved

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Last modified April 25 03:36 EDT 2014. Contains 240994 sequences.