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A197504 A196445(n)/2. 1
1, 3, 7, 9, 11, 19, 23, 27, 31, 43, 47, 49, 59, 67, 71, 79, 81, 83, 103, 107, 121, 127, 131, 139, 151, 163, 167, 179, 191, 199, 211, 223, 227, 239, 243, 251, 263, 271, 283, 307, 311, 331, 343, 347, 359, 361, 367, 379, 383, 419, 431, 439, 443, 463, 467, 479, 487, 491, 499, 503, 523, 529 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..62.

MATHEMATICA

a[n_] := If[n == 2, 1, EulerPhi[n]/{1, 1, 2, 1}[[Mod[n, 4] + 1]]]; aa = {}; Do[If[OddQ[a[n]], AppendTo[aa, n/2]], {n, 2, 1000}]; aa

CROSSREFS

Cf. A055035, A196445.

Sequence in context: A129747 A004614 A112398 * A167800 A270834 A192628

Adjacent sequences:  A197501 A197502 A197503 * A197505 A197506 A197507

KEYWORD

nonn

AUTHOR

Artur Jasinski, Oct 15 2011

STATUS

approved

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Last modified June 15 20:50 EDT 2019. Contains 324145 sequences. (Running on oeis4.)