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%I #6 Dec 05 2013 19:56:36
%S 0,0,31,43,53,61,73,83,97,109,113,127,139,149,1511,1613,179,1811,1913,
%T 2017,2113,2221,2311,2423,2521,2621,2719,2819,2927,3023,3121,3229,
%U 3331,3433,3533,3631,3733,3833,3931,4027,4139,4241,4339,4441,4523,4643,4733
%N a(n) is the largest prime that is the concatenation of n and m for some m < n, or 0 if no such prime exists.
%C Does this prime exist for all n > 2?
%Y Cf. A070219, A089715.
%K base,nonn
%O 1,3
%A _Amarnath Murthy_, Nov 17 2003
%E Edited by _David Wasserman_, Feb 05 2004