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A058321 Number of x with EulerPhi(x)=2^n. 0
3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32 (list; graph; refs; listen; history; internal format)
OFFSET

0,1

EXAMPLE

For n=0 a(0)=2 because Phi(1)=Phi(2)=1.

For n=5, invphi(32) gives 7 values as follows: Phi[{51,64,68,80,96,102,120}]={32,32,32,32,32,32,32}

MAPLE

with(numtheory):[seq(nops(invphi(2^i)), i=1..100)]; a(n)=A014197(2^n)=A014197(A000079(n))

CROSSREFS

A014197, A000079, A058213.

Sequence in context: A004177 A004721 A030544 * A141213 A171950 A184985

Adjacent sequences:  A058318 A058319 A058320 * A058322 A058323 A058324

KEYWORD

nonn

AUTHOR

Labos E. (labos(AT)ana.sote.hu), Dec 11 2000

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Last modified February 14 23:53 EST 2012. Contains 205689 sequences.