OFFSET
1,1
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..10000
MATHEMATICA
Select[Prime[Range[400]], NoneTrue[{10#+3, 10#+9, 3*10^IntegerLength[#]+#, 9*10^IntegerLength[ #]+#}, PrimeQ]&] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Sep 06 2020 *)
PROG
(PARI) lista(nn) = {forprime(p=2, nn, if (!isprime(eval(concat(Str(p), Str(3)))) && ! isprime(eval(concat(Str(p), Str(9)))) && ! isprime(eval(concat(Str(3), Str(p)))) && ! isprime(eval(concat(Str(9), Str(p)))), print1(p, ", ")); ); } \\ Michel Marcus, Sep 14 2014
(Python)
import sympy
from sympy import isprime
from sympy import prime
for n in range(1, 10**3):
..p = str(prime(n))
..if not isprime(p+'3') and not isprime(p+'9') and not isprime('3'+p) and not isprime('9'+p):
....print(int(p), end=', ') # Derek Orr, Sep 16 2014
CROSSREFS
KEYWORD
nonn,base,easy
AUTHOR
Vladimir Shevelev, Sep 13 2014
EXTENSIONS
More terms from Derek Orr, Sep 16 2014
STATUS
approved