|
Search: id:A097974
|
|
|
| A097974 |
|
Sum of distinct prime divisors of n which are <= sqrt(n). |
|
+0
4
|
|
| 0, 0, 0, 2, 0, 2, 0, 2, 3, 2, 0, 5, 0, 2, 3, 2, 0, 5, 0, 2, 3, 2, 0, 5, 5, 2, 3, 2, 0, 10, 0, 2, 3, 2, 5, 5, 0, 2, 3, 7, 0, 5, 0, 2, 8, 2, 0, 5, 7, 7, 3, 2, 0, 5, 5, 9, 3, 2, 0, 10, 0, 2, 10, 2, 5, 5, 0, 2, 3, 14, 0, 5, 0, 2, 8, 2, 7, 5, 0, 7, 3, 2, 0, 12, 5, 2, 3, 2, 0, 10, 7, 2, 3, 2, 5, 5, 0, 9, 3, 7, 0, 5, 0
(list; graph; listen)
|
|
|
OFFSET
|
1,4
|
|
|
LINKS
|
Leroy Quet, Home Page (listed in lieu of email address)
|
|
EXAMPLE
|
2 and 3 are the distinct prime divisors of 12 and both 2 and 3 are <= squareroot of 12. So a(12) = 2 + 3 = 5.
|
|
MAPLE
|
with(numtheory): a:=proc(n) local s, F, f, i: s:=0: F:=factorset(n): f:=nops(F): for i from 1 to f do if F[i]^2<=n then s:=s+F[i] else s:=s: fi od: s; end: seq(a(n), n=1..110); (Deutsch) (Deutsch)
|
|
MATHEMATICA
|
Do[Print[Plus @@ Select[Select[Divisors[n], PrimeQ], #<=Sqrt[n] &]], {n, 1, 100}] (Propper)
|
|
CROSSREFS
|
Sequence in context: A160812 A063918 A163169 this_sequence A139036 A159006 A162660
Adjacent sequences: A097971 A097972 A097973 this_sequence A097975 A097976 A097977
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Leroy Quet, Sep 07 2004
|
|
EXTENSIONS
|
More terms from Ryan Propper (rpropper(AT)stanford.edu), Jul 23 2005
Further terms from Emeric Deutsch (deutsch(AT)duke.poly.edu), Jan 30 2006
|
|
|
Search completed in 0.002 seconds
|
