OFFSET
1,1
LINKS
Alois P. Heinz, Table of n, a(n) for n = 1..10000
James Maynard and Brady Haran, Primes without a 7, Numberphile video (2019)
MATHEMATICA
Select[Prime[Range[6 10^4]], Complement[IntegerDigits[#], {6, 7, 9}] == {} &]
Select[Flatten[Table[FromDigits/@Tuples[{6, 7, 9}, n], {n, 5}]], PrimeQ] (* Harvey P. Dale, Jun 18 2021 *)
PROG
(Magma) [p: p in PrimesUpTo(2*10^5) | Set(Intseq(p)) subset [6, 7, 9]];
CROSSREFS
KEYWORD
nonn,easy,base
AUTHOR
Vincenzo Librandi, Aug 11 2015
STATUS
approved