Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A068963
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
A068963 Sum(phi(d^3)); d|n. +0
2
1, 5, 19, 37, 101, 95, 295, 293, 505, 505, 1211, 703, 2029, 1475, 1919, 2341, 4625, 2525, 6499, 3737, 5605, 6055, 11639, 5567, 12601, 10145, 13627, 10915, 23549, 9595, 28831, 18725, 23009, 23125, 29795, 18685, 49285, 32495, 38551, 29593 (list; graph; listen)
OFFSET

1,2

FORMULA

Also Sum(d*phi(d^2)), d|n; or Sum(d^2*phi(d)); d|n

Also Sum_{k=1..n} (n/gcd(n, k))^2 = Sum_{k=1..n} (lcm(n, k)/k)^2. - Vladeta Jovovic (vladeta(AT)eunet.rs), Dec 29 2002

Multiplicative with a(p^e) = 1 + p^2 + (p-1)(p^(3e)-1)/(p^3-1)

CROSSREFS

Cf. A057660, A056789.

Sequence in context: A029523 A031093 A146861 this_sequence A129828 A146600 A031379

Adjacent sequences: A068960 A068961 A068962 this_sequence A068964 A068965 A068966

KEYWORD

easy,nonn,mult

AUTHOR

Benoit Cloitre (benoit7848c(AT)orange.fr), Apr 06 2002

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 November 25 20:09 EST 2009. Contains 167514 sequences.


AT&T Labs Research