OFFSET
1,1
EXAMPLE
19 is in the sequence because neither of its two digits is prime, 1 being a unit and 9 being the square of 3.
23 is not in the sequence because both 2 and 3 are prime.
29 is in the sequence because 9 is not prime (though 2 is).
MATHEMATICA
Select[Prime[Range[100]], Complement[IntegerDigits[#], {2, 3, 5, 7}] != {} &] (* Alonso del Arte, Aug 27 2012 *)
PROG
(PARI) is_A215927(n)=isprime(n)&apply(x->!isprime(x), eval(Vec(Str(n)))) \\ - M. F. Hasler, Aug 27 2012
(Magma) [p: p in PrimesUpTo(500) | not Set(Intseq(p)) subset [2, 3, 5, 7]]; // Vincenzo Librandi Oct 25 2016
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Luca Brigada Villa, Aug 27 2012
EXTENSIONS
a(55) corrected by Vincenzo Librandi, Oct 25 2016
STATUS
approved