OFFSET
1,1
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..1000
EXAMPLE
13 belongs to this sequence because 3+1-1=2 is prime; 17 because 1+7-1=7; 233 because 2+3+3-1=7; 653 because 6+5+3-1=13.
MATHEMATICA
Select[Prime[Range[200]], PrimeQ[Plus@@ IntegerDigits[#] - 1]&] (* Vincenzo Librandi, Sep 14 2012 *)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Vincenzo Librandi, Oct 28 2009
STATUS
approved