login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A087262 Integer quotient of largest and initial values in 3x+1 iteration, started at n. 1
1, 1, 5, 1, 3, 2, 7, 1, 5, 1, 4, 1, 3, 3, 10, 1, 3, 2, 4, 1, 3, 2, 6, 1, 3, 1, 341, 1, 3, 5, 297, 1, 3, 1, 4, 1, 3, 2, 7, 1, 225, 1, 4, 1, 3, 3, 196, 1, 3, 1, 4, 1, 3, 170, 167, 1, 3, 1, 5, 2, 3, 148, 146, 1, 3, 1, 4, 1, 3, 2, 130, 1, 126, 1, 4, 1, 3, 3, 10, 1, 3, 112, 111, 1, 3, 2, 6, 1, 3, 1, 101 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

Remarkably often, several consecutive terms are identical or close, showing closeness of peaks too: at n=107-111, a(n)=83-86.

If a(n)=1, then the peak is the start-value.

It is conjectured that if peak/initial value is an integer then it equals 1.

LINKS

Table of n, a(n) for n=1..91.

FORMULA

a(n) = floor(A025586(n)/n).

MATHEMATICA

c[x_] := (1-Mod[x, 2])*(x/2)+Mod[x, 2]*(3*x+1)c[1]=1; fpl[x_] := Delete[FixedPointList[c, x], -1] Table[Floor[Max[fpl[w]]/w//N], {w, 1, 256}]

CROSSREFS

Cf. A025586, A056959.

Sequence in context: A136744 A068237 A083345 * A082343 A166125 A199074

Adjacent sequences:  A087259 A087260 A087261 * A087263 A087264 A087265

KEYWORD

nonn

AUTHOR

Labos Elemer, Sep 11 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 May 14 10:08 EDT 2021. Contains 343879 sequences. (Running on oeis4.)