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Iterate the map x -> A289667(x) starting at n; sequence gives primes reached, or -1 if no prime is ever reached.
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%I #20 Aug 05 2017 12:38:58

%S 2,3,71,5,71,7,71,11,23,11,5261,13,17,23,703455573449,17,703455573449,

%T 19,5261,71,703455573449,23,727,17,67,

%U 21544131687786037881228990839860266551231,79,29,21544131687786037881228990839860266551231,31,23,239,71,229,227,37,73

%N Iterate the map x -> A289667(x) starting at n; sequence gives primes reached, or -1 if no prime is ever reached.

%C Base 3 analog of A195264 and A230627.

%H Chai Wah Wu, <a href="/A290329/b290329.txt">Table of n, a(n) for n = 2..47</a>

%p A290329 := proc(n)

%p local nitr ;

%p nitr := n ;

%p while ( not isprime(nitr) and nitr <> 1) do

%p nitr := A289667(nitr) ;

%p end do:

%p return nitr ;

%p end proc:

%p seq(A290329(n),n=1..20) ; # _R. J. Mathar_, Aug 05 2017

%t Table[NestWhile[FromDigits[#, 3] &@ Flatten@ Map[IntegerDigits[#, 3] &, FactorInteger[#] /. {p_, e_} /; p > 0 :> If[e == 1, p, {p, e}]] &, n, ! PrimeQ@ # &], {n, 2, 38}] (* _Michael De Vlieger_, Jul 29 2017 *)

%Y Cf. A290328, A230627, A289667.

%K nonn,base

%O 2,1

%A _Chai Wah Wu_, Jul 27 2017