A172115 Partial sums of A001605.

3, 7, 12, 19, 30, 43, 60, 83, 112, 155, 202, 285, 416, 553, 912, 1343, 1776, 2225, 2734, 3303, 3874, 6845, 11568, 16955, 26266, 35943, 50374, 75935, 106692, 142691, 180202, 231035, 312874, 417785, 547806, 695897, 897004, 1294383, 1728164, 2318205, 2911894, 3516605

Offset: 1

Author

Jonathan Vos Post, Jan 25 2010

Keywords

• hard
• nonn

Examples

			a(1) = 3.
a(2) = 3 + 4 = 7.
a(3) = 3 + 4 + 5 = 12.
		

Links

• Amiram Eldar, Table of n, a(n) for n = 1..56 (calculated from the data at A001605)

Crossrefs

Cf. A001605, A001578, A005478, A086597, A080345.

Extensions

a(40) onwards from Amiram Eldar, Jul 22 2025