OFFSET
1,2
EXAMPLE
phi(1111900875)=1!!*1!!*1!!*1!!*9!!*0!!*0!!*8!!*7!!*5!!, so 1111900875 is in the sequence.
CROSSREFS
KEYWORD
base,easy,nonn,less
AUTHOR
Farideh Firoozbakht, Apr 19 2008
STATUS
approved