OFFSET
1,2
LINKS
Seiichi Manyama, Table of n, a(n) for n = 1..10000
MATHEMATICA
Select[Range[500], PrimeQ[7*10^IntegerLength[#]+#]&] (* Harvey P. Dale, Sep 16 2020 *)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Patrick De Geest, May 15 1998
STATUS
approved