A157780 Denominator of Bernoulli(n, 1/2).

1, 1, 12, 1, 240, 1, 1344, 1, 3840, 1, 33792, 1, 5591040, 1, 49152, 1, 16711680, 1, 104595456, 1, 173015040, 1, 289406976, 1, 22900899840, 1, 201326592, 1, 116769423360, 1, 7689065201664, 1, 1095216660480, 1, 51539607552, 1

Offset: 0

Author

N. J. A. Sloane, Nov 08 2009

Keywords

• nonn
• frac

Comments

Included for completeness, A033469 is the official version of this sequence.

Links

• Vincenzo Librandi, Table of n, a(n) for n = 0..250

Crossrefs

For numerators see A157779.

Programs

Mathematica

Table[Denominator[BernoulliB[n, 1/2]], {n, 0, 50}] (* Vincenzo Librandi, Mar 19 2014 *)

Formula

a(n) = denominator(-(1-2^(1-n))*Bernoulli(n)). - Fabián Pereyra, Dec 31 2022