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A055510 Largest odd prime in sequence obtained in 3x+1 (or Collatz) problem starting at n, or 0 if no such prime is found. 1
0, 0, 5, 0, 5, 5, 17, 0, 17, 5, 17, 5, 13, 17, 53, 0, 17, 17, 29, 5, 0, 17, 53, 5, 29, 13, 1619, 17, 29, 53, 1619, 0, 29, 17, 53, 17, 37, 29, 101, 5, 1619, 0, 43, 17, 17, 53, 1619, 5, 37, 29, 29, 13, 53, 1619, 1619, 17, 43, 29, 101, 53, 61, 1619, 1619, 0, 37, 29, 101, 17, 13 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

Table of n, a(n) for n=1..69.

Index entries for sequences related to 3x+1 (or Collatz) problem

Eric Weisstein's World of Mathematics, Collatz Problem

MATHEMATICA

op[n_]:=Module[{lst=NestWhileList[If[EvenQ[#], #/2, 3#+1]&, n, #!=1&], m}, m= Max[Select[ lst, PrimeQ]]; If[m<3, 0, m]]; Array[op, 70] {* From Harvey P. Dale, Apr 30 2011 *)

CROSSREFS

Cf. A055509.

Sequence in context: A144702 A238192 A156716 * A200397 A265302 A228764

Adjacent sequences:  A055507 A055508 A055509 * A055511 A055512 A055513

KEYWORD

nonn

AUTHOR

G. L. Honaker, Jr., Jun 30 2000

EXTENSIONS

More terms from Larry Reeves (larryr(AT)acm.org), Aug 09 2001

STATUS

approved

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Last modified July 15 04:00 EDT 2020. Contains 335762 sequences. (Running on oeis4.)