A103545 Largest n-digit zeroless prime with nonprime digits.

89, 991, 9949, 99991, 999961, 9999991, 99999989, 999999491, 9999999881, 99999999689, 999999999989, 9999999999161, 99999999999481, 999999999999989, 9999999999999641, 99999999999999961, 999999999999999989, 9999999999999999961, 99999999999999999989

Offset

2,1

Links

Michael S. Branicky, Table of n, a(n) for n = 2..1000

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

Adjacent sequences: A103542 A103543 A103544 * A103546 A103547 A103548

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