|
Search: id:A143235
|
|
| |
|
| 1, 2, 4, 2, 4, 4, 3, 6, 6, 9, 2, 4, 4, 6, 4, 4, 8, 8, 12, 8, 16, 2, 4, 4, 6, 4, 8, 4, 4, 8, 8, 12, 8, 16, 8, 16, 3, 6, 6, 9, 6, 12, 6, 12, 9, 4, 8, 8, 12, 8, 16, 8, 16, 12, 16, 2, 4, 4, 6, 4, 8, 4, 8, 6, 8, 4, 6, 12, 12, 18, 12, 24, 12, 24, 18, 24, 12, 36, 2, 4, 4, 6, 4, 8, 4, 8, 6, 8, 4, 12, 4
(list; table; graph; listen)
|
|
|
OFFSET
|
1,2
|
|
|
COMMENT
|
Row sums = A143236: (1, 6, 10, 24, 20, 56, 32,...).
|
|
FORMULA
|
Triangle read by rows, A130209 * A000012 * A130209; 1<=k<=n. T(n,k) = d(n)*d(k), where d(n) & d(k) = A000005, the number of divisors of n or k.
|
|
EXAMPLE
|
First few rows of the triangle =
1;
2, 4;
2, 4, 4;
3, 6, 6, 9;
2, 4, 4, 6, 4;
4, 8, 8, 12, 8, 16;
2, 4, 4, 6, 4, 8, 4;
4, 8, 8, 12, 8, 16, 8, 16;
3, 6, 6, 9, 6, 12, 6, 12, 9;
...
T(9,6) = 12 = d(9)*d(6) = 3*4.
|
|
CROSSREFS
|
Cf. A000005, A143236.
Sequence in context: A032059 A074075 A004020 this_sequence A069465 A047947 A018838
Adjacent sequences: A143232 A143233 A143234 this_sequence A143236 A143237 A143238
|
|
KEYWORD
|
nonn,tabl
|
|
AUTHOR
|
Gary W. Adamson (qntmpkt(AT)yahoo.com), Aug 01 2008
|
|
|
Search completed in 0.002 seconds
|
