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%I #4 Dec 05 2013 19:56:14
%S 1,2,5,3,7,11,13,17,23,19,29,31,37,41,43,47,53,59,61,67,71,73,79,83,
%T 89,97,101,103,107,109,113,127,131,137,139,149,151,157,163,167,173,
%U 179,181,191,193,197,199,211,223,227,229,233,239,241,251,257,263,269,271,277
%N a(1) = 1; for n>1 a(n) is smallest prime not occurring earlier such that the concatenation of a(n), a(n+1), ..., a(2n-1) is a composite number.
%e 1, 25, 537, 371113, 711131723 are composite numbers. Note that 711131719 is a prime hence a(9) = 23 and not 19.
%Y Cf. A083191.
%K base,nonn
%O 1,2
%A _Amarnath Murthy_, Apr 27 2003
%E Extended by _Ray Chandler_, Jan 04 2009
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