OFFSET
1,3
COMMENTS
The number of positive terms of row n is A000005(n).
The positive terms of row n are the divisors of n.
The number of zeros in row n equals A078152(n).
Row n has length A055086(n).
The sum of row n is A000203(n).
Positive terms give A210959.
It appears that there are only eight rows that do not contain zeros. The indices of these rows are 1, 2, 3, 4, 6, 8, 12, 24, the divisors of 24, see A018253.
For another version see A228812.
EXAMPLE
For n = 60 the 60th row of triangle is [1, 60, 2, 30, 3, 20, 4, 15, 5, 12, 6, 10, 0, 0]. The row length is A055086(60) = 14. The number of zeros is A078152(60) = 2. The number of positive terms is A000005(60) = 12. The row sum is A000203(60) = 168.
Triangle begins:
1;
1, 2;
1, 3;
1, 4, 2;
1, 5, 0;
1, 6, 2, 3;
1, 7, 0, 0;
1, 8, 2, 4;
1, 9, 0, 0, 3;
1, 10, 2, 5, 0;
1, 11, 0, 0, 0;
1, 12, 2, 6, 3, 4;
1, 13, 0, 0, 0, 0;
1, 14, 2, 7, 0, 0;
1, 15, 0, 0, 3, 5;
1, 16, 2, 8, 0, 0, 4;
1, 17, 0, 0, 0, 0, 0;
1, 18, 2, 9, 3, 6, 0;
1, 19, 0, 0, 0, 0, 0;
1, 20, 2, 10, 0, 0, 4, 5;
1, 21, 0, 0, 3, 7, 0, 0;
1, 22, 2, 11, 0, 0, 0, 0;
1, 23, 0, 0, 0, 0, 0, 0;
1, 24, 2, 12, 3, 8, 4, 6;
...
CROSSREFS
KEYWORD
nonn,tabf
AUTHOR
Omar E. Pol, Oct 03 2013
STATUS
approved