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A063439 a(n) = phi(n)^phi(n). 5
1, 1, 4, 4, 256, 4, 46656, 256, 46656, 256, 10000000000, 256, 8916100448256, 46656, 16777216, 16777216, 18446744073709551616, 46656, 39346408075296537575424, 16777216, 8916100448256, 10000000000, 341427877364219557396646723584 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

Number of endofunctions over RRS[n]. Used in proof of Dirichlet theorem to derive characters: a(n)=A000312[A000010(n)] - Labos Elemer, May 27 2002

The sum n=1..infinity 1/phi(n)^phi(n) ~ 2.765711032... and so apparently equals the sum n=1..infinity A014197(n)/n^n where the sequence A014197 is the number of numbers m such that phi(m) = n. Is this a known result? - Gerald McGarvey, May 16 2004

LINKS

Harry J. Smith, Table of n, a(n) for n = 1..200

FORMULA

n log n / (log log n) << log a(n) < n log n. [Charles R Greathouse IV, Jan 19 2012]

PROG

(PARI) { for (n=1, 200, p=eulerphi(n); write("b063439.txt", n, " ", p^p) ) } \\ Harry J. Smith, Aug 21 2009

CROSSREFS

Cf. A000010, A000312, A014197.

Sequence in context: A160365 A264517 A080509 * A218050 A107052 A000790

Adjacent sequences:  A063436 A063437 A063438 * A063440 A063441 A063442

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller, Jul 24 2001

STATUS

approved

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Last modified June 26 04:11 EDT 2019. Contains 324369 sequences. (Running on oeis4.)