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A193276 Composite numbers n such that phi(n) divides 3n - 3. 0
9, 21, 65, 1729, 3201, 4125441 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Next term > 10^9.

LINKS

Table of n, a(n) for n=1..6.

MATHEMATICA

t={}; Do[If[PrimeQ[n]==False&&IntegerQ[(n-1)*3/EulerPhi[n]], Print[n]; AppendTo[t, n]], {n, 2, 10^5}]; t

PROG

(PARI) p=3; forprime(q=5, 1e8, forstep(n=p\4*4, q-1, 4, if((3*n-3)%eulerphi(n)==0, print1(n", "))); p=q) \\ Charles R Greathouse IV, Jul 24 2011

CROSSREFS

Sequence in context: A020288 A147466 A262055 * A173084 A137340 A075640

Adjacent sequences:  A193273 A193274 A193275 * A193277 A193278 A193279

KEYWORD

nonn

AUTHOR

José María Grau Ribas, Jul 20 2011

STATUS

approved

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Last modified October 22 17:39 EDT 2019. Contains 328319 sequences. (Running on oeis4.)