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A053574 Exponent of 2 in phi(n) where phi(n) = A000010(n). 3
0, 0, 1, 1, 2, 1, 1, 2, 1, 2, 1, 2, 2, 1, 3, 3, 4, 1, 1, 3, 2, 1, 1, 3, 2, 2, 1, 2, 2, 3, 1, 4, 2, 4, 3, 2, 2, 1, 3, 4, 3, 2, 1, 2, 3, 1, 1, 4, 1, 2, 5, 3, 2, 1, 3, 3, 2, 2, 1, 4, 2, 1, 2, 5, 4, 2, 1, 5, 2, 3, 1, 3, 3, 2, 3, 2, 2, 3, 1, 5, 1, 3, 1, 3, 6, 1, 3, 3, 3, 3, 3, 2, 2, 1, 3, 5, 5, 1, 2, 3, 2, 5, 1, 4, 4, 2, 1, 2, 2, 3, 3, 4, 4, 2, 3, 3, 3, 1, 5, 5 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,5

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..10000

FORMULA

a(n) = A007814(A000010(n)).

A000010(n) = A053575(n) * 2^a(n). - Antti Karttunen, May 26 2017

EXAMPLE

For n = 513 = 27*19, phi(513) = 4*81 so exponent of 2 is 2, thus a(513) = 2.

MATHEMATICA

IntegerExponent[Array[EulerPhi, 120], 2] (* Michael De Vlieger, Aug 16 2017 *)

PROG

(PARI) vector(66, n, valuation(eulerphi(n), 2)) \\ Joerg Arndt, Apr 22 2011

CROSSREFS

Cf. A000010, A053575, A286572.

Sequence in context: A103684 A105103 A086669 * A321944 A065203 A230798

Adjacent sequences:  A053571 A053572 A053573 * A053575 A053576 A053577

KEYWORD

nonn

AUTHOR

Labos Elemer, Jan 18 2000

EXTENSIONS

Data section extended to 120 terms by Antti Karttunen, May 26 2017

STATUS

approved

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Last modified March 21 20:30 EDT 2019. Contains 321382 sequences. (Running on oeis4.)