A068565 Denominators of Sum_{k=1..n} 1/(k * 2^k).

2, 8, 3, 192, 960, 1920, 1680, 215040, 645120, 64512, 1419264, 11354112, 147603456, 295206912, 46126080, 47233105920, 802962800640, 802962800640, 15256293212160, 61025172848640, 61025172848640, 122050345697280

Offset: 1

Author

Benoit Cloitre, Mar 25 2002

Keywords

• easy
• frac
• nonn

Comments

Sum_{k>=1} 1/(k * 2^k) = log(2).

Crossrefs

Cf. A068566.

Programs

PARI

a(n) = denominator(sum(k=1, n, 1/(k * 2^k))); \\ Michel Marcus, Jun 26 2019