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A300065
Numbers k such that the number of residues modulo k of the maximum order is different from phi(phi(k)).
5
8, 12, 21, 24, 28, 33, 36, 42, 44, 56, 57, 63, 65, 66, 69, 72, 76, 77, 80, 84, 88, 91, 92, 93, 99, 108, 114, 117, 124, 126, 129, 130, 132, 133, 138, 141, 145, 147, 152, 154, 161, 168, 171, 172, 177, 182, 184, 185, 186, 188, 189, 195, 196, 198, 201, 207, 208, 209, 213, 216, 217, 228, 231, 234, 236, 237, 240, 248, 249, 252, 253, 258, 260, 264, 265, 266, 268, 273, 275, 276, 279, 282
OFFSET
1,1
COMMENTS
Numbers k such that A111725(k) is not equal to A010554(k).
The ratio a(n)/n tends to 1 as n grows.
LINKS
Peter J. Cameron and D. A. Preece, Primitive lambda-roots, 2014.
T. W. Müller and J.-C. Schlage-Puchta, On the number of primitive lambda-roots, Acta Arithmetica, Vol. 115 (2004), pp. 217-223.
MATHEMATICA
q[n_] := Count[(t = Table[MultiplicativeOrder[k, n], {k, Select[Range[n], CoprimeQ[n, #] &]}]), Max[t]] != EulerPhi[EulerPhi[n]]; Select[Range[300], q] (* Amiram Eldar, Oct 12 2021 *)
CROSSREFS
Complement of A300064.
Union of {8} and set difference of A024619 and A300080.
Sequence in context: A072843 A354069 A350615 * A072902 A269705 A189322
KEYWORD
nonn
AUTHOR
Max Alekseyev, Feb 23 2018
STATUS
approved