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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A117358 a(n) = A032742(A032742(A032742(n))) = ((n/lpf(n))/lpf(n/lpf(n)))/lpf((n/lpf(n))/lpf(n/lpf(n))), where lpf=A020639, least prime factor. 7
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 1, 1, 4, 1, 1, 1, 3, 1, 1, 1, 5, 1, 1, 1, 1, 1, 1, 1, 6, 1, 1, 1, 1, 1, 3, 1, 7, 1, 1, 1, 5, 1, 1, 1, 8, 1, 1, 1, 1, 1, 1, 1, 9, 1, 1, 1, 1, 1, 1, 1, 10, 3, 1, 1, 7, 1, 1, 1, 11, 1, 5, 1, 1, 1, 1, 1, 12, 1, 1, 1, 5, 1, 1, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,16

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..65537

Eric Weisstein's World of Mathematics, Least Prime Factor

FORMULA

a(n) = A032742(A032742(A032742(n))) = A032742(A054576(n)) = A054576(n)/A115561(n).

a(A037144(n)) = 1, a(A033987(n)) > 1.

PROG

(Scheme) (define (A117358 n) (A032742 (A032742 (A032742 n)))) ;; Antti Karttunen, Dec 07 2017

CROSSREFS

Cf. A014673, A032742, A037144, A033987, A054576, A115561.

Sequence in context: A225174 A059895 A190867 * A294333 A205617 A204112

Adjacent sequences:  A117355 A117356 A117357 * A117359 A117360 A117361

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller, Mar 10 2006

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.

License Agreements, Terms of Use, Privacy Policy. .

Last modified August 20 06:54 EDT 2018. Contains 313909 sequences. (Running on oeis4.)