A103544 Least n-digit zeroless prime with nonprime digits.

11, 149, 1181, 11119, 111119, 1111169, 11111119, 111111181, 1111111181, 11111111449, 111111111149, 1111111111441, 11111111111411, 111111111111691, 1111111111111181, 11111111111111119, 111111111111111161

Offset

2,1

Links

Robert Israel, Table of n, a(n) for n = 2..999

Maple

f:= proc(n) local t, x, L, y;
  t:= (10^n-1)/9;
  for x from 0 to 5^n-1 do
    L:= subs({1=3, 2=5, 3=7, 4=8}, convert(x, base, 5));
    y:= t+add(10^(i-1)*L[i], i=1..nops(L));
    if isprime(y) then return y fi
  od;
  FAIL
end proc:
map(f, [$2..20]); # Robert Israel, Sep 28 2018

Mathematica

NextPrim[n_] := Block[{k = n + 1}, While[ !PrimeQ[k], k++ ]; k]; f[n_] := Block[{np = NextPrim[(10^n - 1)/9 - 1]}, While[ Union[ Join[{1, 4, 6, 8, 9}, IntegerDigits[np]]] != {1, 4, 6, 8, 9}, np = NextPrim[np]]; np]; Table[ f[n], {n, 2, 18}] (* Robert G. Wilson v, Mar 23 2005 *)
ndzp[n_]:=Module[{np=NextPrime[FromDigits[PadRight[{}, n, 1]]]}, While[ !SubsetQ[ {1, 4, 6, 8, 9}, IntegerDigits[ np]], np =NextPrime[np]]; np]; Join[{11}, Array[ndzp, 16, 3]] (* Harvey P. Dale, Aug 28 2021 *)

Prog

(Python)
from sympy import isprime
from itertools import product
def a(n):
    for p in product("14689", repeat=n):
        t = int("".join(p))
        if isprime(t): return t
print([a(n) for n in range(2, 22)]) # Michael S. Branicky, Aug 20 2022

Crossrefs

Sequence in context: A217722 A261536 A175635 * A038141 A307072 A142083

Adjacent sequences: A103541 A103542 A103543 * A103545 A103546 A103547

Keyword

base,nonn

Author

Ray G. Opao, Mar 22 2005

Extensions

More terms from Robert G. Wilson v, Mar 23 2005

Status

approved