login
a(1) = 3. For n > 1, a(n) is the least unused number such that the concatenation a(n)a(n-1)...a(2)a(1) is prime.
16

%I #8 Dec 05 2013 19:56:36

%S 3,1,6,9,4,20,13,29,19,2,7,18,12,41,36,30,72,25,27,8,28,42,47,114,85,

%T 38,16,117,177,24,11,66,34,53,37,264,48,126,96,87,39,261,99,65,124,

%U 419,21,147,55,321,240,62,40,69,92,60,49,287,289,393,227,745,84,149,58,54,141

%N a(1) = 3. For n > 1, a(n) is the least unused number such that the concatenation a(n)a(n-1)...a(2)a(1) is prime.

%C Is this a rearrangement of the natural numbers?

%e 3, 13, 613, 9613, 49613, 2049613, ... etc. are primes.

%Y Cf. A089711.

%K base,nonn

%O 1,1

%A _Amarnath Murthy_, Nov 17 2003

%E More terms from _Ray Chandler_, Nov 21 2003

%E Edited by _Charles R Greathouse IV_, Apr 29 2010