%I
%S 2,19,199,1999,49999,199999,2999999,19999999,799999999,9199999999,
%T 59999999999,959999999999,9919999999999,59999999999999,
%U 499999999999999,9299999999999999,99919999999999999,994999999999999999,9991999999999999999,29999999999999999999
%N Smallest ndigit prime having at least n1 digits equal to 9.
%H Michel Lagneau, Michael De Vlieger and Robert G. Wilson v, <a href="/A268707/b268707.txt">Table of n, a(n) for n = 1..1225</a>
%t f[n_] := Block[{k = 0, p = {}, r = (10^n  1), s = Range@ 10  10}, While[k < n  0, AppendTo[p, Select[r + 10^k*s, PrimeQ]]; k++]; p = Min@ Flatten@ p]; Array[f, 20]
%o (PARI) a(n)=my(t=10^n1,p); forstep(d=n1,0,1, forstep(k=8,1,1, p=t10^d*k; if(ispseudoprime(p), return(p)))); 1 \\ _Charles R Greathouse IV_, Mar 21 2016
%Y Cf. A037071, A241100, A268702  A268706, A241206, A266148.
%K nonn,base
%O 1,1
%A _Michel Lagneau_, _Michael De Vlieger_ and _Robert G. Wilson v_, Feb 11 2016
