作
f(x) = ∑{n>=1}{[x^(2n+1)]/(4n+2) - [x^(2n+2)]/(4n+4)}
= (-1/2)*∑{n>=1}{[(-x)^(2n+1)]/(2n+1) + [(-x)^(2n+2)]/(2n+2)}
= (-1/2)*∑{n>=3}[(-x)^n]/n
= (-1/2)*{1/(1+x) - 1 - x - (x^2)/2},
则
∑{n>=1}{1/(4n+2) - 1/(4n+4)} = f(1) = ……
作
f(x) = ∑{n>=1}{[x^(2n+1)]/(4n+2) - [x^(2n+2)]/(4n+4)}
= (-1/2)*∑{n>=1}{[(-x)^(2n+1)]/(2n+1) + [(-x)^(2n+2)]/(2n+2)}
= (-1/2)*∑{n>=3}[(-x)^n]/n
= (-1/2)*{1/(1+x) - 1 - x - (x^2)/2},
则
∑{n>=1}{1/(4n+2) - 1/(4n+4)} = f(1) = ……