A100561 Denominator of Sum_{k=0..[n/2]} 1/binomial(n,k).

1, 1, 2, 3, 12, 10, 60, 105, 140, 63, 280, 1155, 27720, 25740, 8008, 9009, 16380, 17017, 6126120, 2909907, 5542680, 2645370, 232792560, 111546435, 535422888, 128707425, 2974571600, 717084225, 80313433200, 77636318760, 2329089562800, 4512611027925, 546983154900

Offset

0,3

Links

Table of n, a(n) for n=0..32.

Example

1, 3/2, 4/3, 17/12, 13/10, 77/60, 128/105, 167/140, 73/63, 319/280, 1294/1155, 30697/27720, 28211/25740, 8707/8008, 9728/9009, 17587/16380, 18181/17017, ... = A100560/A100561

Mathematica

Denominator[Table[Sum[1/Binomial[n, k], {k, 0, Floor[n/2]}], {n, 0, 40}]] (* Harvey P. Dale, Dec 24 2014 *)

Crossrefs

Sequence in context: A068550 A093432 A212303 * A334721 A081529 A002944

Adjacent sequences: A100558 A100559 A100560 * A100562 A100563 A100564

Keyword

nonn,frac

Author

N. J. A. Sloane, Nov 28 2004

Status

approved