login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
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 (list; graph; refs; listen; history; text; internal format)
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,changed

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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified August 19 23:59 EDT 2022. Contains 356231 sequences. (Running on oeis4.)