What is ∫0x11+t2dt\int_0^x \frac{1}{1+t^2} dt∫0x1+t21dt expressed as a power series?
∑n=0∞(−1)nx2n+12n+1\sum_{n=0}^{\infty} \frac{(-1)^n x^{2n+1}}{2n+1}∑n=0∞2n+1(−1)nx2n+1
∑n=0∞(−1)nx2n+1\sum_{n=0}^{\infty} (-1)^n x^{2n+1}∑n=0∞(−1)nx2n+1
∑n=0∞(−1)nx2n2n\sum_{n=0}^{\infty} \frac{(-1)^n x^{2n}}{2n}∑n=0∞2n(−1)nx2n
∑n=0∞(−1)n(2n)x2n−1\sum_{n=0}^{\infty} (-1)^n (2n) x^{2n-1}∑n=0∞(−1)n(2n)x2n−1