A071994 a(n) = Sum_{k=1..n} A003159(k).

1, 4, 8, 13, 20, 29, 40, 52, 65, 80, 96, 113, 132, 152, 173, 196, 221, 248, 276, 305, 336, 369, 404, 440, 477, 516, 557, 600, 644, 689, 736, 784, 833, 884, 936, 989, 1044, 1101, 1160, 1220, 1281, 1344, 1408, 1473, 1540, 1608, 1677, 1748, 1821, 1896, 1972, 2049

Offset: 1

Author

Benoit Cloitre, Jun 17 2002

Keywords

• easy
• nonn

Links

• Amiram Eldar, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A003159.

Programs

Mathematica

Accumulate @ Select[Range[100], EvenQ[IntegerExponent[#, 2]] &] (* Amiram Eldar, Jan 16 2022 *)

Formula

a(n) ~ 3*n^2/4 + O(n*log(n)). - Amiram Eldar, Jan 16 2022