OFFSET
1,2
COMMENTS
Column k lists the odd numbers repeated k times starting in row k^2.
1 together with the first differences of the row sums give the divisor function A000005.
T(n,k) is also the total number of divisors of all positive integers <= n on the edges of k-th triangle in the diagram of divisors (see link section). See also A212119.
LINKS
Omar E. Pol, , Diagram of divisors, figure 1, figure 2
FORMULA
T(n,k) = Sum_{j=1..n) A212119(j,k).
EXAMPLE
Written as an irregular triangle the sequence begins:
1;
3;
5;
7, 1;
9, 1;
11, 3;
13, 3;
15, 5;
17, 5, 1;
19, 7, 1;
21, 7, 1;
23, 9, 3;
25, 9, 3;
27, 11, 3;
29, 11, 5;
31, 13, 5, 1;
33, 13, 5, 1;
35, 15, 7, 1;
37, 15, 7, 1;
39, 17, 7, 3;
41, 17, 9, 3;
43, 19, 9, 3;
45, 19, 9, 3;
47, 21, 11, 5;
49, 21, 11, 5, 1;
CROSSREFS
KEYWORD
nonn,tabf
AUTHOR
Omar E. Pol, Jul 02 2012
EXTENSIONS
Definition changed by Franklin T. Adams-Watters, Jul 12 2012
STATUS
approved