OFFSET
1,1
MATHEMATICA
lpp[n_]:=Module[{p=2, c=10^n}, While[!AllTrue[p*c-{1, 3, 7, 9}, PrimeQ], p= NextPrime[ p]]; p]; Array[lpp, 30] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Jun 12 2016 *)
PROG
(Python)
import sympy
from sympy import isprime
from sympy import prime
def a(n):
..for k in range(1, 10**8):
....if isprime(prime(k)*10**n-1) and isprime(prime(k)*10**n-3) and isprime(prime(k)*10**n-7) and isprime(prime(k)*10**n-9):
......return prime(k)
n = 1
while n < 100:
..print(a(n), end=', ')
..n+=1
(PARI) a(n)=for(k=1, 10^8, if(ispseudoprime(prime(k)*10^n-1) && ispseudoprime(prime(k)*10^n-3) && ispseudoprime(prime(k)*10^n-7) && ispseudoprime(prime(k)*10^n-9), return(prime(k))))
n=1; while(n<100, print1(a(n), ", "); n++)
CROSSREFS
KEYWORD
nonn
AUTHOR
Derek Orr, Jun 04 2014
STATUS
approved