A166722 a(n) is the number of divisors of A166721(n).

1, 3, 5, 9, 7, 15, 21, 27, 11, 25, 45, 13, 35, 33, 63, 75, 39, 81, 49, 17, 55, 105, 135, 99, 19, 65, 51, 189, 77, 125, 117, 147, 225, 165, 57, 243, 91, 175, 23, 85, 315, 195, 297, 153, 231, 95, 405, 245, 69, 375, 351, 119, 275, 441, 171, 121, 273, 567, 495, 255, 525

Offset: 1

Author

Alexander Isaev (i2357(AT)mail.ru), Oct 20 2009

Keywords

• easy
• nonn

Comments

This is a permutation of the odd numbers A005408. - Alois P. Heinz, Mar 04 2018

Examples

			a(8) = A000005(A166721(8)) = A000005(900) = A000005(2^2 * 3^2 * 5^2) = (2+1)*(2+1)*(2+1) = 27.
		

Links

• Amiram Eldar, Table of n, a(n) for n = 1..10000 (terms 1..300 from Alois P. Heinz)

Crossrefs

Cf. A000005, A005408, A048691, A136404, A152674, A166721.

Formula

a(n) = A000005(A166721(n)).

Extensions

Proper definition (and removal of obscure Comments entries) by Jon E. Schoenfield, Mar 03 2018