How can I make Mathematica return a series expansion in the form $\sum_{j=0}^\infty \dots$ instead of $a_0 + a_1x^1 + \dots + a_{n-1}x^{n-1}+ O(x^n)$
31721
Series with specific notation
32637
What is the sum of this series: $\displaystyle\sum_{n=0}^{\infty} \dfrac{a^n}{(3n)!}$
78632
Summation equation for $2^{x-1}$
138313
How to sum $\sum_{n=1}^{\infty} \frac{1}{n^2 + a^2}$?
119987
Show the series $ \sum_{j=1}^{\infty} \frac{(2^j)+ j}{(3^j) - j} $ converges
152802
How find series $\sum_{n=1}^{\infty}\frac{(-1)^{[\sqrt[m]{n}]}}{n^a}$?
65653
Find a closed form of the series $\sum_{n=0}^{\infty} n^2x^n$
139307
Closed form expression for infinite series
99420
Compute $\sum_{n=1}^\infty \frac{1}{(n+1)\sqrt[]{n}+n\sqrt[]{n+1}}$
132613
Testing the series $\sum\limits_{n=1}^{\infty} \frac{1}{n^{k + \cos{n}}}$
148143
Find the sum to n terms as well as the sum to infinity of the series:
79105
Expand series unevaluated
123951
Problem calculating sum of convergent series of $\sum_{n=2}^{\infty} \frac{1}{n^{2}-1}$
19899
infinite series of the form $\sum\limits_{k=1}^{\infty}\frac{1}{a^{k}+1}$
155367
summation of multiplying series with negative terms
127806
How to find the sum of the series $\sum_{k=2}^\infty \frac{1}{k^2-1}$?
1379
Summation of $n^2x^n$ terms