%I #11 Jul 01 2013 18:30:12
%S 10,14,15,18,20,21,25,26,27,28,35,36,37,39,40,42,49,50,52,56,63,64,65,
%T 67,72,74,79,80,84,91,96,100,101,104,109,111,112,125,127,128,144,168,
%U 181,185,192,200,211,224,256,269,281,288,293,307,336,353,379
%N Places n where A225867(n) = 4.
%C Note that the proportion of prime terms has a tendency to increase. For example,
%C 1 from the first 20 terms; 6 from the first 40 terms; 16 from the first 60 terms; 34 from the first 80 terms; 53 from the first 100 terms; 90 from the first 140 terms. We conjecture that this proportion asymptotically tends to 1.
%Y Cf. A225867, A225868, A226977.
%K nonn
%O 1,1
%A _Vladimir Shevelev_, Jun 27 2013