OFFSET
1,1
COMMENTS
This sequence has the terms from A067933 (all primes), plus 511 and 3359231 that are not primes.
Checked up to x<70000000
a(14) > 10^11. [From Donovan Johnson, Aug 08 2010]
PROG
(PARI) for(x=1, 70000000, if(((x)+1)%eulerphi((x)-1)==0, print((x))))
CROSSREFS
KEYWORD
nonn
AUTHOR
Jorge Coveiro, Jul 25 2006
EXTENSIONS
a(13) from Donovan Johnson, Aug 08 2010
STATUS
approved