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A103545
Largest n-digit zeroless prime with nonprime digits.
2
89, 991, 9949, 99991, 999961, 9999991, 99999989, 999999491, 9999999881, 99999999689, 999999999989, 9999999999161, 99999999999481, 999999999999989, 9999999999999641, 99999999999999961, 999999999999999989, 9999999999999999961, 99999999999999999989
OFFSET
2,1
LINKS
MATHEMATICA
PrevPrim[n_] := Block[{k = n - 1}, While[ !PrimeQ[k], k-- ]; k]; f[n_] := Block[{pp = PrevPrim[ 10^n]}, While[ Union[ Join[{1, 4, 6, 8, 9}, IntegerDigits[pp]]] != {1, 4, 6, 8, 9}, pp = PrevPrim[pp]]; pp]; Table[ f[n], {n, 2, 18}] (* Robert G. Wilson v, Mar 26 2005 *)
PROG
(Python)
from sympy import isprime
from itertools import product
def a(n):
for p in product("98641", repeat=n):
t = int("".join(p))
if isprime(t): return t
print([a(n) for n in range(2, 22)]) # Michael S. Branicky, Aug 10 2022
CROSSREFS
Cf. A103544.
Sequence in context: A289852 A158716 A093289 * A118368 A197399 A183321
KEYWORD
base,nonn
AUTHOR
Ray G. Opao, Mar 22 2005
EXTENSIONS
More terms from Jonathan Vos Post, Mar 23 2005
a(7) to a(12) from Jonathan Vos Post, Mar 23 2005
a(13) to a(18) from Robert G. Wilson v, Mar 26 2005
a(19) and beyond from Michael S. Branicky, Aug 10 2022
STATUS
approved