A238015 Denominator of (2*n+1)!*8*Bernoulli(2*n,1/2).

1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 2, 1, 2, 2, 4, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 2, 1, 2, 2, 4, 1, 1, 1, 2, 1, 2, 2, 4, 1, 2, 2, 4, 2, 4, 4, 8, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 2, 1, 2, 2, 4, 1, 1, 1, 2, 1, 2, 2, 4, 1, 2, 2, 4, 2, 4, 4, 8, 1, 1, 1, 2, 1

Offset: 0

Author

Robert Israel, Feb 17 2014

Keywords

• nonn
• frac

Comments

It appears that a(n) is 1 for n in A095736, 2 for n in A014312, 4 for n in A014313, 8 for n in A023688, 16 for n in A023689, 32 for n in A023690, 64 for n in A023691. - Michel Marcus, Feb 18 2014

Examples

			For n=15, (2*15+1)!*8*Bernoulli(2*15,1/2) = -79147239268966167007717425917182573906640625/2 so a(15) = 2.
		

Links

• Robert Israel, Table of n, a(n) for n = 0..2000

Crossrefs

Cf. A033473.

Programs

Maple

seq(denom((2*n+1)!*8*bernoulli(2*n,1/2)), n=0 .. 100);

Mathematica

Table[Denominator[(2 n + 1)! 8 BernoulliB[2 n, 1/2]], {n, 0, 200}] (* Vincenzo Librandi, Feb 18 2014 *)