|
Search: id:A074701
|
|
|
| A074701 |
|
Numbers n such that n = sum( d dividing phi(n), mu(phi(d))*phi(n)/d ). |
|
+0
2
|
| |
|
|
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
|
Cf. A000351. [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Sep 23 2008]
Sequence in context: A005761 A009002 A119882 this_sequence A140127 A154143 A101611
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
|
|
|
Search completed in 0.002 seconds
|
