%I #5 Jan 08 2019 09:12:41
%S 1,9,77,27,49,33,91,51,133,39,119,69,143,21,121,57,203,93,169,63,247,
%T 81,299,147,209,123,217,87,187,111,253,153,259,99,289,129,221,159,161,
%U 141,301,177,319,117,329,201,287,219,361,183,343,237,581,171,341,273,323
%N a(1) = 1, a(n) = smallest composite number not occurring earlier such that the concatenation a(n-1) and a(n) is a prime.
%Y Cf. A075607, A075609, A075610.
%K base,nonn
%O 1,2
%A _Amarnath Murthy_, Sep 28 2002
%E More terms from _Michel ten Voorde_ Jun 23 2003