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A053578 Values of cototient function for A053577. 1
1, 1, 2, 1, 4, 1, 4, 1, 8, 1, 8, 8, 1, 1, 1, 16, 16, 1, 1, 16, 1, 1, 1, 1, 32, 1, 32, 1, 1, 32, 32, 1, 1, 1, 1, 1, 1, 64, 1, 1, 1, 1, 1, 64, 1, 64, 1, 64, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 128, 1, 1, 1, 1, 1, 128, 1, 1, 1, 1, 1, 128, 1, 128, 128, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

Except for 2^0 = 1, there are only finitely many values of k such that cototient(k) = 2^m for fixed m.

LINKS

Table of n, a(n) for n=1..94.

EXAMPLE

For p prime, cototient[p] = 1. Smallest values for which cototient[x] = 2^w are A058764(w) = A007283(w-1) = 3*2^(w-1) = 6, 12, 24, 48, 96, 192, .., 49152 for w = 2, 3, 4, 5, 6, ..., 15. [Corrected by M. F. Hasler, Nov 10 2016]

CROSSREFS

Cf. A051953, A053577, A058764, A007283.

Sequence in context: A126210 A040005 A193306 * A168177 A216864 A263432

Adjacent sequences:  A053575 A053576 A053577 * A053579 A053580 A053581

KEYWORD

nonn

AUTHOR

Labos Elemer, Jan 18 2000

EXTENSIONS

Edited and corrected by M. F. Hasler, Nov 10 2016

STATUS

approved

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Last modified August 13 05:41 EDT 2020. Contains 336442 sequences. (Running on oeis4.)