OFFSET
1,2
COMMENTS
a(9) > 2*10^5. - Robert Price, Jan 19 2015
MATHEMATICA
Do[ If[ PrimeQ[ 10*11^n + 1 ], Print[ n ] ], {n, 0, 1000} ]
Select[Range[0, 4000], PrimeQ[(10*11^# + 1)] &] (* Vincenzo Librandi, Sep 28 2012 *)
PROG
(PARI) is(n)=ispseudoprime(10*11^n+1) \\ Charles R Greathouse IV, Jun 13 2017
CROSSREFS
KEYWORD
nonn
AUTHOR
Robert G. Wilson v, Sep 08 2000
EXTENSIONS
a(5) from Vincenzo Librandi, Sep 28 2012
a(6)-a(8) from Robert Price, Jan 19 2015
STATUS
approved