login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A065970 a(n) = n^2 * Sum_{primes p dividing n} (1 - 1/p^2). 1
0, 3, 8, 12, 24, 59, 48, 48, 72, 171, 120, 236, 168, 339, 416, 192, 288, 531, 360, 684, 824, 843, 528, 944, 600, 1179, 648, 1356, 840, 2339, 960, 768, 2048, 2019, 2376, 2124, 1368, 2523, 2864, 2736, 1680, 4619, 1848, 3372, 3744, 3699, 2208 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
LINKS
PROG
(PARI) { for (n=1, 1000, s=0; p=2; while (p<=n, if(n%p == 0, s+=1 - 1/p^2); p=nextprime(p + 1)); write("b065970.txt", n, " ", n^2*s) ) } \\ Harry J. Smith, Nov 05 2009
CROSSREFS
Sequence in context: A007434 A128303 A123906 * A326890 A024463 A092954
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Dec 09 2001
STATUS
approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified March 29 11:45 EDT 2024. Contains 371278 sequences. (Running on oeis4.)