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A117283 Numbers n for which the cototient n-phi(n) is a cube. 0
1, 2, 3, 5, 7, 11, 12, 13, 14, 16, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 63, 67, 71, 73, 79, 81, 83, 89, 96, 97, 101, 103, 107, 109, 112, 113, 115, 124, 127, 128, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 187, 191, 193, 197, 199, 211, 223, 227 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

EXAMPLE

63 is in the sequence because 63-phi(63)=27, which is a cube

MATHEMATICA

Select[Range[230], IntegerQ[(# - EulerPhi[ # ])^(1/3)] &] - Stefan Steinerberger (stefan.steinerberger(AT)gmail.com), Apr 24 2006

CROSSREFS

Sequence in context: A104192 A104193 A117288 * A198096 A137923 A163753

Adjacent sequences:  A117280 A117281 A117282 * A117284 A117285 A117286

KEYWORD

nonn

AUTHOR

Luc Stevens (lms022(AT)yahoo.com), Apr 23 2006

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Last modified February 13 22:36 EST 2012. Contains 205567 sequences.