login
This site is supported by donations to The OEIS Foundation.

 

Logo

Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing.
Other ways to donate

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A061436 Number of steps for trajectory of n to reach 1 under the map that sends x -> x/3 if x mod 3 = 0, x -> x+3-(x mod 3) if x is not 0 mod 3 (for a 2nd time when n starts at 1). 1
2, 2, 1, 4, 4, 3, 3, 3, 2, 6, 6, 5, 6, 6, 5, 5, 5, 4, 5, 5, 4, 5, 5, 4, 4, 4, 3, 8, 8, 7, 8, 8, 7, 7, 7, 6, 8, 8, 7, 8, 8, 7, 7, 7, 6, 7, 7, 6, 7, 7, 6, 6, 6, 5, 7, 7, 6, 7, 7, 6, 6, 6, 5, 7, 7, 6, 7, 7, 6, 6, 6, 5, 6, 6, 5, 6, 6, 5, 5, 5, 4, 10, 10, 9, 10, 10, 9, 9, 9, 8, 10, 10, 9, 10, 10, 9, 9, 9, 8, 9, 9 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

This sequence is generated by the pari program below for m=3,p=1. Other values of m and p also converge but not necessarily to 1. For m =2 and p=1 we have the count of steps for the x+1 problem. m=prime and p=m+1 usually converge to 1 but break down for certain values of n. E.g. 17 locks at n=34, 23 at n=49 29 at n=91. I verified m=7 for n up to 100000. 100000 requires 157 steps to reach 1.

LINKS

Table of n, a(n) for n=1..101.

Cino Hilliard, The x+1 conjecture

EXAMPLE

x = 1. step1:x=1+3-1=3 step2: x=3/3=1. Count =2 steps.

PROG

(PARI) multxp2(n, m, p) = { print1(2" "); for(j=1, n, x=j; c=0; while(x>1, r = x%m; if(r==0, x=x/m, x=x*p+m-r); print1(x" "); ); ) }

CROSSREFS

Sequence in context: A110664 A193922 A319534 * A214095 A213948 A136787

Adjacent sequences:  A061433 A061434 A061435 * A061437 A061438 A061439

KEYWORD

easy,nonn

AUTHOR

Cino Hilliard, Mar 29 2003

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
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified December 13 06:26 EST 2019. Contains 329968 sequences. (Running on oeis4.)