def taylor_term(self, n, x, *previous_terms):
if n < 0 or n % 2 == 0:
return S.Zero
else:
x = Basic.sympify(x)
a, b = ((n-1)//2), 2**(n+1)
B = Basic.bernoulli(n+1)
F = Basic.Factorial(n+1)
return (-1)**a * b*(b-1) * B/F * x**n
