login
Denominator of (2*n+1)!*8*Bernoulli(2*n,1/2).
3

%I #21 Feb 19 2014 14:25:21

%S 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,

%T 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,

%U 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

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

%C 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

%H Robert Israel, <a href="/A238015/b238015.txt">Table of n, a(n) for n = 0..2000</a>

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

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

%t Table[Denominator[(2 n + 1)! 8 BernoulliB[2 n, 1/2]], {n, 0, 200}] (* _Vincenzo Librandi_, Feb 18 2014 *)

%Y Cf. A033473.

%K nonn,frac

%O 0,16

%A _Robert Israel_, Feb 17 2014