A138881 Array read by rows: row n lists divisors of n-th positive triangular number A000217(n).

1, 1, 3, 1, 2, 3, 6, 1, 2, 5, 10, 1, 3, 5, 15, 1, 3, 7, 21, 1, 2, 4, 7, 14, 28, 1, 2, 3, 4, 6, 9, 12, 18, 36, 1, 3, 5, 9, 15, 45, 1, 5, 11, 55, 1, 2, 3, 6, 11, 22, 33, 66, 1, 2, 3, 6, 13, 26, 39, 78, 1, 7, 13, 91, 1, 3, 5, 7, 15, 21, 35, 105

Offset: 1

Author

Omar E. Pol, Apr 11 2008

Keywords

• easy
• nonn
• tabf

Examples

			Array begins:
1
1, 3
1, 2, 3, 6
1, 2, 5, 10
1, 3, 5, 15
1, 3, 7, 21
1, 2, 4, 7, 14, 28
		

Crossrefs

Cf. A000217, A133021, A133031, A138882.