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A104775 Smallest semiprime containing exactly n 9's. 1

%I

%S 9,299,5999,19999,899999,5999999,79999999,299999999,1999999999,

%T 49999999999,499999999999,1999999999999,29999999999999,

%U 199999999999999,1999999999999999,29999999999999999,599999999999999999

%N Smallest semiprime containing exactly n 9's.

%C When (if ever) does this differ from A106663? - _Andrew S. Plewe_, Apr 11 2007

%e a(2)=299 because 299 is the smallest semiprime containing exactly two 9's.

%K base,nonn

%O 1,1

%A _Shyam Sunder Gupta_, Apr 24 2005

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Last modified April 4 21:43 EDT 2020. Contains 333238 sequences. (Running on oeis4.)