%I A090519
%S A090519 2,13,23,13,89,19,7,47,67,13,17,157,17,313,107,409,151,773,149,409,109,
%T A090519 13,29,211,7,19,149,431,859,43,109,167,277,13,2293,173,907,107,1087,617,
%U A090519 449,1013,73,1249,743,109,233,499,191,479
%N A090519 Smallest prime p such that floor[(10^n)/p] is prime, or 0 if no such 
               number exists.
%C A090519 Conjecture: No term is zero. Subsidiary Sequence: Number of primes in 
               floor[(10^n)/p], p is a prime. a(1) = 3, the primes are 10/2, floor[10/
               3] and 10/5.
%e A090519 a(5) = 89, as floor[(10^5)/89]= 1123 is the largest such prime.
%t A090519 <<NumberTheory`; Do[k = 2; While[ !PrimeQ[Floor[10^n / k]], k = NextPrime[k]]; 
               Print[k], {n, 1, 50}] (Propper)
%Y A090519 Cf. A090517, A090518, A090520.
%Y A090519 Sequence in context: A127485 A061385 A156179 this_sequence A018540 A045388 
               A118796
%Y A090519 Adjacent sequences: A090516 A090517 A090518 this_sequence A090520 A090521 
               A090522
%K A090519 base,nonn
%O A090519 1,1
%A A090519 Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Dec 07 2003
%E A090519 Corrected and extended by Ryan Propper (rpropper(AT)stanford.edu), Jun 
               19 2005