|
Search: id:A136178
|
|
|
| A136178 |
|
Irregular array read by rows: row n contains the GCDs of each pair of consecutive positive divisors of n. |
|
+0 4
|
|
| 1, 1, 1, 2, 1, 1, 1, 3, 1, 1, 2, 4, 1, 3, 1, 1, 5, 1, 1, 1, 1, 2, 6, 1, 1, 1, 7, 1, 1, 5, 1, 2, 4, 8, 1, 1, 1, 3, 3, 9, 1, 1, 2, 1, 5, 10
(list; table; graph; listen)
|
|
|
OFFSET
|
2,4
|
|
|
COMMENT
|
Each row has d(n)-1 terms, where d(n) is the number of positive divisors of n. The first row listed is row 2.
|
|
EXAMPLE
|
The positive divisors of 20 are 1,2,4,5,10,20. GCD(1,2)=1. GCD(2,4)=2. GCD(4,5)=1. GCD(5,10)=5. And GCD(10,20)=10. So row 20 is (1,2,1,5,10).
|
|
CROSSREFS
|
Cf. A136179, A136180, A136181.
Sequence in context: A101950 A104562 A111603 this_sequence A047140 A047150 A102054
Adjacent sequences: A136175 A136176 A136177 this_sequence A136179 A136180 A136181
|
|
KEYWORD
|
more,nonn,tabl
|
|
AUTHOR
|
Leroy Quet (qq-quet(AT)mindspring.com), Dec 19 2007
|
|
|
Search completed in 0.002 seconds
|