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 A066497 Least number k such that phi(k) / Carmichael lambda(k) = 2n. 1

%I #6 Jun 02 2012 22:41:12

%S 8,24,63,80,275,252,1247,240,513,825,1541,455,4187,3277,1891,1040,

%T 14111,819,43739,2200,2107,4623,6533,1365,15251,8321,8829,6235,13747,

%U 2387,116003,2720,13333,42333,14981,3276,33227,131217,12403,4400,61337

%N Least number k such that phi(k) / Carmichael lambda(k) = 2n.

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

%H T. D. Noe, <a href="/A066497/b066497.txt">Table of n, a(n) for n = 1..1000</a>

%t 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

%K nonn

%O 1,1

%A _Robert G. Wilson v_, Jan 13 2002

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Last modified November 29 10:41 EST 2023. Contains 367429 sequences. (Running on oeis4.)