%I #7 Jul 29 2017 13:16:11

%S 1,1,1,1,2,1,3,4,4,2,1,2,1,2,1,1,2,4,3,1,1,3,1,3,4,1,1,2,2,1,2,1,1,2,

%T 4,3,1,1,1,1,5,1,5,1,2,2,1,3,3,1,4,1,2,4,2,4,2,2,5,11,1,1,4,4,2,1,3,3,

%U 1,6,4,2,1,13,1,5,3,1,5,6,1,2,2,3,4,1,1,4,2,1,5,1,1,5,1,2,4,2,6,1,2,3,3,1,4

%N Smallest number prefixed with corresponding term of the sequence of numbers == 1, 3, 7 or 9 (mod 10), i.e., (1, 3, 7, 9, 11, 13, 17, 19, 21, 23, 27, 29, 31, 33, 37, 39, ...) that yields a prime.

%e The term corresponding to 61 is 4 as 161, 261 and 361 are composite.

%K base,easy,nonn

%O 0,5

%A _Amarnath Murthy_, Sep 28 2003

%E More terms from _David Wasserman_, Jul 27 2005