A173697 a(n) = ceiling(A013984(n)/2).

1, 0, 1, 1, 1, 2, 3, 4, 6, 10, 16, 25, 40, 63, 100, 159, 253, 402, 640, 1017, 1617, 2570, 4087, 6498, 10331, 16427, 26118, 41528, 66030, 104988, 166931, 265421, 422020, 671014, 1066916, 1696402, 2697289, 4288703, 6819061, 10842344, 17239385, 27410714, 43583183, 69297495, 110183389, 175192180, 278556508

Offset: 0

Author

Roger L. Bagula, Nov 25 2010

Keywords

• nonn
• easy
• less

Links

• G. C. Greubel, Table of n, a(n) for n = 0..1000

Crossrefs

Cf. A013984.

Programs

Mathematica

Ceiling[CoefficientList[Series[1/(1 - x^2 - x^3 - x^4 - x^5 - x^6 - x^7), {x, 0, 50}], x]/2] (* G. C. Greubel, Nov 23 2016 *)

Formula

a(n) = ceiling(A013984(n)/2).

Extensions

Erroneous leading zeros deleted by G. C. Greubel, Nov 23 2016