%I #22 Jul 30 2017 03:53:43
%S 0,0,4,0,3,0,3,1,1,0,7,0,2,2,20,0,19,0,5,2,19,0,4,1,1,52,1,0,51,0,1,2,
%T 1,2,1,0,1,4,51,0,2,0,1,20,5,0
%N Iterate the map x -> A289667(x) starting at n; sequence gives number of steps to reach a prime, or -1 if no prime is ever reached.
%C Base 3 analog of A230626. See A290350 for the trajectory of 48.
%C If a(48) != -1, then a(48) > 120. - _Chai Wah Wu_, Jul 29 2017
%t Table[-1 + Length@ NestWhileList[FromDigits[#, 3] &@ Flatten@ Map[IntegerDigits[#, 3] &, FactorInteger[#] /. {p_, e_} /; p > 0 :> If[e == 1, p, {p, e}]] &, n, ! PrimeQ@ # &], {n, 2, 47}] (* _Michael De Vlieger_, Jul 29 2017 *)
%Y Cf. A289667, A230626, A195264, A290350, A290329.
%K nonn,more,base
%O 2,3
%A _Chai Wah Wu_, Jul 27 2017
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