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 A164328 a(n) is the smallest n-digit prime term of A158594 and zero if there is no such number. 5
 7, 11, 271, 1033, 18289, 133733, 1045493, 11939237, 103333333, 1342313221, 10300335833, 145933933339, 1332523411733, 11653733331833 (list; graph; refs; listen; history; text; internal format)
 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 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

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Last modified May 23 07:08 EDT 2019. Contains 323508 sequences. (Running on oeis4.)