|
|
A193511
|
|
a(n) = Sum of even divisors of Omega(n), a(1) = 0.
|
|
3
|
|
|
0, 0, 0, 2, 0, 2, 0, 0, 2, 2, 0, 0, 0, 2, 2, 6, 0, 0, 0, 0, 2, 2, 0, 6, 2, 2, 0, 0, 0, 0, 0, 0, 2, 2, 2, 6, 0, 2, 2, 6, 0, 0, 0, 0, 0, 2, 0, 0, 2, 0, 2, 0, 0, 6, 2, 6, 2, 2, 0, 6, 0, 2, 0, 8, 2, 0, 0, 0, 2, 0, 0, 0, 0, 2, 0, 0, 2, 0, 0, 0
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,4
|
|
COMMENTS
|
Omega(n) = number of prime divisors of n counted with multiplicity : A001222 (also called bigomega(n)).
a(1) = 0 by convention.
|
|
LINKS
|
|
|
FORMULA
|
(End)
|
|
EXAMPLE
|
a(16) = 6 because Omega(16) = 4 and the sum of the even divisors of 4 {2, 4} is 6.
|
|
MATHEMATICA
|
Table[Total[Select[Divisors[PrimeOmega[n]], EvenQ[ # ]&]], {n, 58}]
|
|
PROG
|
(PARI)
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|