OFFSET
1,1
LINKS
Michael S. Branicky, Table of n, a(n) for n = 1..10000
EXAMPLE
If k = 10, then k9 = 109 (prime).
If k = 160, then k9 = 1609 (prime).
If k = 320, then k9 = 3209 (prime).
MAPLE
select(n-> isprime(10*n+9), [10*i$i=1..300])[]; # Alois P. Heinz, Jan 19 2024
MATHEMATICA
Select[Range[10, 2210, 10], PrimeQ[FromDigits[Prepend[{9}, #]]]&] (* James C. McMahon, Jan 19 2024 *)
PROG
(Python)
from sympy import isprime
from itertools import count, islice
def agen(): yield from (k for k in count(10, 10) if isprime(10*k+9))
print(list(islice(agen(), 53))) # Michael S. Branicky, Jan 19 2024
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Parthasarathy Nambi, Mar 01 2005
STATUS
approved