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%I #5 Dec 05 2013 19:56:21
%S 1,1,0,1,1,0,1,0,0,1,1,0,0,1,0,1,1,0,1,2,0,1,0,0,1,1,0,0,1,0,1,1,0,2,
%T 1,0,1,0,0,1,2,0,0,1,0,1,1,0,1,1,0,1,0,0,3,2,0,0,1,0,1,2,0,1,1,0,2,0,
%U 0,1,1,0,0,1,0,2,1,0,1,4,0,1,0,0,1,1,0,0,2,0,1,1,0,1,1,0,2,0,0,6,1,0,0,2,0
%N Smallest k such that 10^k + 2n-1 is a prime >10, or 0 if no such k exists. Index of the smallest power of 10 which when increased by the n-th odd number yields a prime.
%C Most of the terms are 0, 1 or 2. Subsidiary sequence: Index of the first occurrence of n. Conjecture: There exists a finite M such that a(n) < M for all n.
%e a(10) = 1 as 10^1 + 19 = 29 is a prime.
%K nonn
%O 1,20
%A _Amarnath Murthy_, Sep 09 2003
%E More terms from _David Wasserman_, May 24 2005
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