OFFSET
1,2
COMMENTS
a(12) > 25*10^9. - Donovan Johnson, Jun 09 2011
a(16) > 2*10^12. - Giovanni Resta, Aug 12 2019
EXAMPLE
n=59815: phi(n) = 40992, phi(n+1) = 29904 = rev(phi(n)).
MATHEMATICA
Select[Range[60000], IntegerReverse[EulerPhi[# + 1]] == EulerPhi[#] &] (* Giovanni Resta, Aug 12 2019 *)
PROG
(PARI) isok(n) = eulerphi(n) == fromdigits(Vecrev(digits(eulerphi(n+1)))); \\ Michel Marcus, Aug 12 2019
CROSSREFS
KEYWORD
nonn,base,more
AUTHOR
Labos Elemer, Sep 20 2002
EXTENSIONS
a(9)-a(11) from Donovan Johnson, Jun 09 2011
a(12)-a(15) from Giovanni Resta, Aug 12 2019
STATUS
approved