|
Search: id:A100565
|
|
|
| A100565 |
|
Card{(x,y,z) : x<=y<=z, x|n, y|n, z|n, GCD(x,y)=1, GCD(x,z)=1, GCD(y,z)=1}. |
|
+0
1
|
|
| 1, 2, 2, 3, 2, 5, 2, 4, 3, 5, 2, 8, 2, 5, 5, 5, 2, 8, 2, 8, 5, 5, 2, 11, 3, 5, 4, 8, 2, 15, 2, 6, 5, 5, 5, 13, 2, 5, 5, 11, 2, 15, 2, 8, 8, 5, 2, 14, 3, 8, 5, 8, 2, 11, 5, 11, 5, 5, 2, 25, 2, 5, 8, 7, 5, 15, 2, 8, 5, 15, 2, 18, 2, 5, 8, 8, 5, 15, 2, 14, 5, 5, 2, 25, 5, 5, 5, 11, 2, 25, 5, 8, 5, 5, 5, 17
(list; graph; listen)
|
|
|
OFFSET
|
1,2
|
|
|
COMMENT
|
Also Card{(x,y,z) : x<=y<=z and LCM(x,y)=n, LCM(x,z)=n, LCM(y,z)=n}.
|
|
FORMULA
|
a(n) = (tau(n^3)+3*tau(n)+2)/6.
|
|
CROSSREFS
|
Cf. A000005, A048785, A066620, A070919, A086222, A086165, A048691, A018892, A063647.
Adjacent sequences: A100562 A100563 A100564 this_sequence A100566 A100567 A100568
Sequence in context: A141822 A033099 A018892 this_sequence A010846 A073023 A007012
|
|
KEYWORD
|
easy,nonn
|
|
AUTHOR
|
Vladeta Jovovic (vladeta(AT)Eunet.yu), Nov 28 2004
|
|
|
Search completed in 0.002 seconds
|
