OFFSET
1,1
COMMENTS
The digits are prime numbers.
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..1000
MATHEMATICA
Flatten[Table[Select[FromDigits/@Tuples[{2, 5, 7}, n], PrimeQ], {n, 6}]]
PROG
(Magma) [p: p in PrimesUpTo(100000) | Set(Intseq(p)) subset [2, 5, 7]];
(Python)
from sympy import primerange
def ok(p): return set(str(p)) <= set("257")
def aupto(limit): return [p for p in primerange(2, limit+1) if ok(p)]
print(aupto(222557)) # Michael S. Branicky, Feb 05 2021
CROSSREFS
KEYWORD
nonn,base,easy
AUTHOR
Vincenzo Librandi, Jul 28 2012
STATUS
approved