OFFSET
1,1
LINKS
MATHEMATICA
Flatten[Table[Select[FromDigits/@Tuples[{7, 9}, n], PrimeQ], {n, 7}]] (* Vincenzo Librandi, Jul 28 2012 *)
PROG
(Magma) [p: p in PrimesUpTo(7977997) | Set(Intseq(p)) subset [7, 9]]; // Vincenzo Librandi, Jul 28 2012
CROSSREFS
KEYWORD
nonn,base
AUTHOR
EXTENSIONS
Edited by M. F. Hasler, Jul 26 2015
STATUS
approved