Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A074701
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
A074701 Numbers n such that n = sum( d dividing phi(n), mu(phi(d))*phi(n)/d ). +0
1
1, 3, 5, 25, 125, 625, 3125, 15625, 78125 (list; graph; listen)
OFFSET

1,2

COMMENT

Does sequence consist of 1,3 and all powers of 5? Answer from Lambert Klasen, Oct 07 2005: Yes! See attached file.

LINKS

Lambert Klasen, Notes on A074701

MAPLE

with(numtheory): a:=proc(n) local div: div:=convert(divisors(phi(n)), list): if add(mobius(phi(div[j]))*phi(n)/div[j], j=1..nops(div))=n then n else fi end: seq(a(n), n=1..5000); (Deutsch)

CROSSREFS

Sequence in context: A005761 A009002 A119882 this_sequence A140127 A101611 A069060

Adjacent sequences: A074698 A074699 A074700 this_sequence A074702 A074703 A074704

KEYWORD

more,nonn

AUTHOR

Benoit Cloitre (benoit7848c(AT)orange.fr), Sep 03 2002

EXTENSIONS

2 more terms from Emeric Deutsch (deutsch(AT)duke.poly.edu), Mar 27 2005

page 1

Search completed in 0.002 seconds

Lookup | Welcome | Find friends | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
More pages | Superseeker | Maintained by N. J. A. Sloane (njas@research.att.com)

Last modified August 19 23:53 EDT 2008. Contains 142930 sequences.


AT&T Labs Research