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

 

Logo

Annual Appeal: Please make a donation to keep the OEIS running. In 2018 we replaced the server with a faster one, added 20000 new sequences, and reached 7000 citations (often saying "discovered thanks to the OEIS").
Other ways to donate

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A057446 To get next term, multiply by 13, add 1 and discard any prime factors < 13. 14
73, 19, 31, 101, 73, 19, 31, 101, 73, 19, 31, 101, 73, 19, 31, 101, 73, 19, 31, 101, 73, 19, 31, 101, 73, 19, 31, 101, 73, 19, 31, 101, 73, 19, 31, 101, 73, 19, 31, 101, 73, 19, 31, 101, 73, 19, 31, 101, 73, 19, 31, 101, 73, 19, 31, 101, 73, 19, 31, 101 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

COMMENTS

This is the `13x+1' map. The `Px+1 map': if x is divisible by any prime < P then divide out these primes one at a time starting with the smallest; otherwise multiply x by P and add 1.

REFERENCES

Murad A. AlDamen, Smarandache Notion Journal, "Murad iterating function" [details?].

Murad A. AlDamen, Murad iterating function, Journal of University of Jerash, 2001, to appear.

LINKS

Table of n, a(n) for n=0..59.

Eric Weisstein's World of Mathematics, Collatz problem

EXAMPLE

73 -> 19*73+1 = 950 = 2*5^2*19 -> 19, so second term is 19.

CROSSREFS

Cf. A057216, A057522 (long version), A057534, A057614.

Sequence in context: A051325 A249276 A102050 * A033393 A153646 A179516

Adjacent sequences:  A057443 A057444 A057445 * A057447 A057448 A057449

KEYWORD

nonn

AUTHOR

Murad A. AlDamen (Divisibility(AT)yahoo.com), Oct 17 2000

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 16 07:12 EST 2018. Contains 318158 sequences. (Running on oeis4.)