

A230627


Prime reached in A230626, or 1 if no prime is reached.


11



2, 3, 31, 5, 11, 7, 11, 23, 31, 11, 43, 13, 23, 29, 251, 17, 23, 19, 251, 31, 43, 23, 47, 43, 463, 29, 23, 29, 127, 31, 31, 59, 23, 47, 8093, 37, 83, 61, 127, 41, 179, 43, 467, 463, 23, 47, 83, 127, 467, 113, 173, 53, 47, 23, 179, 241, 127, 59, 349, 61, 179
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OFFSET

2,1


COMMENTS

I also observe that the numbers 1007 and 1269 are mapped to each other by that map, as are the numbers 1503 and 3751 (see the bfile submitted by Chai Wah Wu for A230625). So a(1007) = a(1269) = a(1503) = a(3751) = 1.  David J. Seal, Jun 16 2017
a(217) = a(255) = a(446) = a(558) = a(717) = a(735) = a(775) = a(945) = a(958) = 1 since the trajectory either converges to (1007,1269) or to (1503,3751).  Chai Wah Wu, Jun 16 2017
The latest information seems to be that for numbers less than 12388, all trajectories either end at a fixed point or in a cycle of length 2.  N. J. A. Sloane, Jul 27 2017


LINKS

N. J. A. Sloane, Three (No, 8) Lovely Problems from the OEIS, Experimental Mathematics Seminar, Rutgers University, Oct 05 2017, Part I, Part 2, Slides. (Mentions this sequence)


MATHEMATICA

fn[n_] := FromDigits[Flatten[IntegerDigits[ReplaceAll[FactorInteger[n], {x_, 1} > {x}], 2]], 2];
Table[NestWhile[fn, n, # != 1 && ! PrimeQ[#] &], {n, 2, 50}] (* Robert Price, Mar 16 2020 *)


CROSSREFS

See A287875 for these same numbers written in binary.
See A288847 for where the values 1 occur.


KEYWORD

sign,base


AUTHOR



EXTENSIONS



STATUS

approved



