OFFSET
1,1
COMMENTS
The digits are prime numbers excluding 7.
LINKS
Michael S. Branicky, Table of n, a(n) for n = 1..10000 (terms 1..1000 from Vincenzo Librandi)
MATHEMATICA
Flatten[Table[Select[FromDigits/@Tuples[{2, 3, 5}, n], PrimeQ], {n, 7}]]
PROG
(Magma) [p: p in PrimesUpTo(300000) | Set(Intseq(p)) subset [2, 3, 5]];
(Python)
from sympy import isprime
from itertools import count, islice, product
def agen(): yield from (k for d in count(1) for k in (int("".join(p)) for p in product("235", repeat=d)) if isprime(k))
print(list(islice(agen(), 41))) # Michael S. Branicky, Dec 04 2022
CROSSREFS
KEYWORD
nonn,base,easy
AUTHOR
Vincenzo Librandi, Jul 28 2012
STATUS
approved