This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A139391 Next odd term in Collatz trajectory with starting value n. 15
 1, 1, 5, 1, 1, 3, 11, 1, 7, 5, 17, 3, 5, 7, 23, 1, 13, 9, 29, 5, 1, 11, 35, 3, 19, 13, 41, 7, 11, 15, 47, 1, 25, 17, 53, 9, 7, 19, 59, 5, 31, 21, 65, 11, 17, 23, 71, 3, 37, 25, 77, 13, 5, 27, 83, 7, 43, 29, 89, 15, 23, 31, 95, 1, 49, 33, 101, 17, 13, 35, 107, 9, 55, 37, 113, 19, 29 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 COMMENTS a(n) = A006370(n) iff n mod 4 = 2; a(A016825(n))=A006370(A016825(n)); a(n) = A000265(A006370(n)). a(A160967(n)) = 1. [From Reinhard Zumkeller, May 31 2009] REFERENCES Friedrich L. Bauer, 'Der (ungerade) Collatz-Baum', Informatik Spektrum 31 (Springer, April 2008). LINKS R. Zumkeller, Table of n, a(n) for n = 1..10000 Eric Weisstein's World of Mathematics, Collatz Problem Wikipedia, Collatz conjecture [From Reinhard Zumkeller, May 31 2009] FORMULA a(n) = if A006370(n) is odd then A006370(n) else a(A006370(n)). MATHEMATICA a[n_]:=Select[NestWhileList[If[EvenQ[#], #/2, 3#+1] &, n, #>1 &], OddQ]; Prepend[Table[If[EvenQ[n], a[n][[1]], a[n][[2]]], {n, 2, 77}], 1] (* Jayanta Basu, May 27 2013 *) CROSSREFS Sequence in context: A179261 A154567 A260210 * A196612 A110635 A179773 Adjacent sequences:  A139388 A139389 A139390 * A139392 A139393 A139394 KEYWORD nonn AUTHOR Reinhard Zumkeller, Apr 17 2008 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.