OFFSET
0,5
COMMENTS
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..200
EXAMPLE
a(0) = -1/1, a(1) = 2/2, a(2) = -6/6, a(3) = 30/30, a(4) = -210/42 =-5.
MATHEMATICA
a[0] = -1; a[1] = 1; a[n_] := (-1)^(n+1)*(2*n)!/(2^(n-1)*n!*Denominator[BernoulliB[2*n-2]]); Table[a[n], {n, 0, 20}] (* Jean-François Alcover, Feb 24 2014 *)
CROSSREFS
KEYWORD
sign
AUTHOR
Paul Curtz, Feb 24 2014
EXTENSIONS
More terms from Jean-François Alcover, Feb 24 2014
STATUS
approved