A020637 - OEIS

%I #11 Feb 16 2013 16:33:19

%S 7,11,13,17,19,23,29,31,37,41,43,47,53,61,67,73,79,83,89,97,101,103,

%T 107,127,131,139,149,151,163,167,173,179,181,197,199,211,223,227,233,

%U 239,257,263,283,307,311,313,331,353,379,389,397,409,419,431,439,479

%N Smallest nonempty set S containing prime divisors of 10k+9 for each k in S.

%H Nathaniel Johnston, <a href="/A020637/b020637.txt">Table of n, a(n) for n = 1..168</a> (full sequence)

%K nonn,fini,full

%O 1,1

%A _David W. Wilson_