login
The OEIS is supported by
the many generous donors to the OEIS Foundation
.
Hints
(Greetings from
The On-Line Encyclopedia of Integer Sequences
!)
A238193
Position of first occurrence of (4^n - 1)/3 in
A238192
.
1
3, 21, 75, 151, 1365, 5461, 14563, 87381, 184111, 932067
(
list
;
graph
;
refs
;
listen
;
history
;
text
;
internal format
)
OFFSET
2,1
COMMENTS
Another version of
A237661
.
Is this (apart from the missing 1) the same as
A054646
? -
R. J. Mathar
, Mar 30 2014
LINKS
Table of n, a(n) for n=2..11.
MATHEMATICA
Collatz[n_] := NestWhileList[If[EvenQ[#], #/2, 3 # + 1] &, n, # > 1 &]; t = Table[c = Collatz[n]; co = Select[c, OddQ]; If[Length[co] == 1, 0, co[[-2]]], {n, 10000}]; Flatten[Table[Position[t, (4^n - 1)/3, 1, 1], {n, 2, 7}]]
CROSSREFS
Cf.
A002450
((4^n-1)/3),
A070165
(Collatz trajectories),
A238192
.
Sequence in context:
A188667
A083564
A281008
*
A054646
A228317
A322228
Adjacent sequences:
A238190
A238191
A238192
*
A238194
A238195
A238196
KEYWORD
nonn
,
more
AUTHOR
T. D. Noe
, Feb 21 2014
STATUS
approved
Lookup
|
Welcome
|
Wiki
|
Register
|
Music
|
Plot 2
|
Demos
|
Index
|
Browse
|
More
|
WebCam
Contribute new seq. or comment
|
Format
|
Style Sheet
|
Transforms
|
Superseeker
|
Recents
The OEIS Community
| Maintained by
The OEIS Foundation Inc.
License Agreements, Terms of Use, Privacy Policy.
.
Last modified April 23 03:30 EDT 2024. Contains 371906 sequences. (Running on oeis4.)