OFFSET
1,1
COMMENTS
For formulas and references see A277002 which is the main entry for this rational sequence.
FORMULA
a(n) = denominator(b(2*n-1)) with b(n) = Bernoulli(n+1, 1/2)/(n*(n+1)) for n>=1, b(0)=0.
EXAMPLE
The underlying rational sequence b(n) starts:
0, -1/24, 0, 7/2880, 0, -31/40320, 0, 127/215040, 0, -511/608256, ...
MAPLE
b := n -> `if`(n=0, 0, bernoulli(n+1, 1/2)/(n*(n+1))):
a := n -> denom(b(2*n-1)):
seq(a(n), n=1..19);
MATHEMATICA
b[n_] := BernoulliB[n+1, 1/2]/(n(n+1));
a[n_] := Denominator[b[2n-1]];
Array[a, 19] (* Jean-François Alcover, Sep 09 2018 *)
CROSSREFS
KEYWORD
nonn,frac
AUTHOR
Peter Luschny, Sep 26 2016
STATUS
approved