A164328 a(n) is the smallest n-digit prime term of A158594 and zero if there is no such number.

7, 11, 271, 1033, 18289, 133733, 1045493, 11939237, 103333333, 1342313221, 10300335833, 145933933339, 1332523411733, 11653733331833

Offset

1,1

Comments

It seems that for all n, a(n)>0.

A164327(n) gives us smallest n-digit term of A158594. So A164328(n)>=A164327(n).

Links

Table of n, a(n) for n=1..14.

Example

a(5)=18289 so all the seven numbers 18289, 318289, 138289, 183289, 182389,
182839 & 182893 are primes.

Mathematica

pp[n_, k_] := Catch[Block[{d = IntegerDigits@n}, Do[If[! PrimeQ[ FromDigits[ Insert[d, k, i]]], Throw[False]], {i, 1+Length@d}]; True]]; a[n_] := Catch[ Block[{p = NextPrime[10^(n-1)]}, While[p < 10^n, If[pp[p, 3], Throw@p, p = NextPrime@p]]; 0]]; a /@ Range[8] (* Giovanni Resta, Aug 13 2013 *)

Crossrefs

Cf. A158594, A164327, A164329, A228148-A228150.

Sequence in context: A231329 A322950 A201120 * A301736 A096952 A143602

Adjacent sequences: A164325 A164326 A164327 * A164329 A164330 A164331

Keyword

base,hard,more,nonn

Author

Farideh Firoozbakht, Sep 22 2009

Extensions

a(11)-a(13) from Donovan Johnson, Apr 14 2010

a(14) from Giovanni Resta, Aug 11 2013

Status

approved