OFFSET
1,1
COMMENTS
Or, primes with minimal digit 8.
LINKS
Michael S. Branicky, Table of n, a(n) for n = 1..10000 (terms 1..1000 from Vincenzo Librandi)
MATHEMATICA
Select[Prime[Range[80000]], Min[IntegerDigits[#]] == 8 &] (* Zak Seidov, May 07 2005 *)
Flatten[Table[Select[FromDigits/@Tuples[{8, 9}, n], PrimeQ], {n, 8}]] (* Vincenzo Librandi, Jul 27 2012 *)
PROG
(PARI) for(nd=1, 9, p=vector(nd, i, 10^(nd-i))~; forvec(v=vector(nd, i, [8+(i==nd), 9]), isprime(v*p) && print1(v*p", "))) \\ M. F. Hasler, Mar 18 2010
(Python)
from sympy import isprime
from itertools import count, islice, product
def agen(): # generator of terms
for d in count(2):
for first in product("89", repeat=d-1):
t = int("".join(first) + "9")
if isprime(t): yield t
print(list(islice(agen(), 30))) # Michael S. Branicky, Nov 15 2022
CROSSREFS
KEYWORD
nonn,base
AUTHOR
EXTENSIONS
Edited by N. J. A. Sloane, Jan 26 2008 at the suggestion of Lekraj Beedassy
STATUS
approved