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A043343 Numbers n such that there is no k > n such that phi(k) = phi(n), where phi is Euler's totient function. 5
2, 6, 12, 18, 22, 30, 42, 46, 54, 58, 60, 62, 66, 90, 94, 98, 106, 118, 120, 126, 134, 138, 142, 150, 158, 162, 166, 174, 198, 206, 210, 214, 240, 242, 250, 254, 262, 270, 274, 276, 278, 282, 294, 298, 302, 318, 330, 334, 346, 348, 354, 358, 378, 382, 394, 398 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
FORMULA
A066659(a(n)) = 0.
A028476(a(n)) = a(n).
MATHEMATICA
Flatten@ Position[#, 0] &@ Table[k = n + 1; While[And[k <= 2 n + 1, EulerPhi@ k != EulerPhi@ n], k++]; Boole[k < 2 n + 1] k, {n, 400}] (* Michael De Vlieger, Dec 31 2016 *)
CROSSREFS
Cf. A066659.
Sequence in context: A263269 A262503 A263082 * A066080 A319270 A071707
KEYWORD
nonn
AUTHOR
Vladeta Jovovic, Jan 12 2002
EXTENSIONS
Offset corrected by Paul Tek, Sep 25 2015
Definition clarified by Alonso del Arte, Dec 31 2016
STATUS
approved

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Last modified March 29 00:26 EDT 2024. Contains 371264 sequences. (Running on oeis4.)