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A066497 Least number k such that phi(k) / Carmichael lambda(k) = 2n. 1
8, 24, 63, 80, 275, 252, 1247, 240, 513, 825, 1541, 455, 4187, 3277, 1891, 1040, 14111, 819, 43739, 2200, 2107, 4623, 6533, 1365, 15251, 8321, 8829, 6235, 13747, 2387, 116003, 2720, 13333, 42333, 14981, 3276, 33227, 131217, 12403, 4400, 61337 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Except when Phi(n) = Lambda(n), the value Phi(n)/Lambda(n) must be even.

LINKS

T. D. Noe, Table of n, a(n) for n = 1..1000

MATHEMATICA

nn = 75; a = Table[0, {nn}]; found = 0; k = 0; While[found < nn, k++; b = EulerPhi[k]/CarmichaelLambda[k]; If[IntegerQ[b/2] && b/2 <= nn && a[[b/2]] == 0, a[[b/2]] = k; found++]]; a

CROSSREFS

Sequence in context: A049724 A060602 A066605 * A205963 A208895 A111071

Adjacent sequences:  A066494 A066495 A066496 * A066498 A066499 A066500

KEYWORD

nonn

AUTHOR

Robert G. Wilson v, Jan 13 2002

STATUS

approved

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Last modified July 30 23:12 EDT 2021. Contains 346365 sequences. (Running on oeis4.)