|
Search: id:A136183
|
|
|
| A136183 |
|
a(n) = Sum_{k=1 to d(n)-1} LCM(b(k),b(k+1)), where b(k) is the kth positive divisor of n and d(n) = number of positive divisors of n. |
|
+0
4
|
|
| 0, 2, 3, 6, 5, 14, 7, 14, 12, 22, 11, 44
(list; graph; listen)
|
|
|
OFFSET
|
1,2
|
|
|
COMMENT
|
a(n) = sum of the terms in row n of A136181.
|
|
EXAMPLE
|
The positive divisors of 20 are 1,2,4,5,10,20. LCM(1,2)=2. LCM(2,4)=4. LCM(4,5)=20. LCM(5,10)=10. And LCM(10,20)=20. So a(20) = 2+4+20+10+20 = 56.
|
|
CROSSREFS
|
Cf. A136180, A136181, A136182.
Adjacent sequences: A136180 A136181 A136182 this_sequence A136184 A136185 A136186
Sequence in context: A002517 A053570 A129647 this_sequence A100211 A071257 A067392
|
|
KEYWORD
|
more,nonn
|
|
AUTHOR
|
Leroy Quet (qq-quet(AT)mindspring.com), Dec 19 2007
|
|
|
Search completed in 0.002 seconds
|
