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A103113 Numbers n such that phi(n)=phi(d_1^d_1)*phi(d_2^d_2)*...*phi(d_k^d_k) where d_1 d_2 ... d_k is the decimal expansion of n. 2
1, 113125, 2322432, 21332611, 2115124224, 3111423252, 3412115322, 12451223232, 116222114125, 1141433232511, 2231521231226, 2334121141253, 3222154622111, 4211413132352, 15123362231122, 21123234615111, 32125124213611, 114231133412352, 233152112133612 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
a(38) (if it exists) >= 10^18. - Hiroaki Yamanouchi, Sep 10 2014
LINKS
Hiroaki Yamanouchi, Table of n, a(n) for n = 1..37
EXAMPLE
21332611 is in the sequence because phi(21332611)=phi(2^2)*phi(1^1)*phi(3^3)*phi(3^3)*phi(2^2)*phi(6^6)*phi(1^1)*phi(1^1).
MATHEMATICA
Do[h=IntegerDigits[m]; l=Length[h]; If[Min[h]>0&&EulerPhi[m]== Product[EulerPhi[h[[k]]^h[[k]]], {k, l}], Print[m]], {m, 200000000}]
CROSSREFS
Cf. A104898.
Sequence in context: A177275 A303999 A252036 * A179922 A122511 A172549
KEYWORD
nonn,base
AUTHOR
Farideh Firoozbakht, Mar 29 2005
EXTENSIONS
a(5)-a(17) from Max Alekseyev, May 10 2009, May 05 2010, Aug 22 2013
a(18)-a(19) from Hiroaki Yamanouchi, Sep 10 2014
STATUS
approved

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Last modified March 4 15:24 EST 2024. Contains 370532 sequences. (Running on oeis4.)