query: Solving this summation: $\sum_{i=1}^k i\cdot2^i$
positive_passages.docid: 6416
positive_passages.text: How can I evaluate $\sum_{n=0}^\infty(n+1)x^n$?
negative_passages.docid: 36361
negative_passages.text: How to calculate the summation $(\sum_{p = k}^{n} \binom{n}{p}) / 2^n$ quickly?
negative_passages.docid: 151085
negative_passages.text: Simplify the sum $ \sum_{i=0}^{k}(-1)^i i \binom{n}{i} \binom{n}{k-i}$
negative_passages.docid: 54753
negative_passages.text: What does $\sum_{i=1}^{10} 2$ mean exactly?
negative_passages.docid: 142303
negative_passages.text: Alternating sum of binomial coefficients multiplied by (1/k+1)
negative_passages.docid: 148949
negative_passages.text: Find the value of $\sum_{k=1}^{n} k \binom {n} {k}$
negative_passages.docid: 37007
negative_passages.text: Evaluating $\sum_{k=1}^{n} \frac{1}{k(k+1)}$
negative_passages.docid: 153409
negative_passages.text: Sum of $1+\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+\frac{1}{6}+\frac{1}{8}+\frac{1}{9}+\frac{1}{12}+\cdots$
negative_passages.docid: 30851
negative_passages.text: Find the summation $\frac{1}{1!}+\frac{1+2}{2!}+\frac{1+2+3}{3!}+ \cdots$
negative_passages.docid: 91933
negative_passages.text: Evaluate $\sum_{k=1}^nk\cdot k!$
negative_passages.docid: 92704
negative_passages.text: Prove that $\sum_{k=1}^{n}k\binom{n}{k}=n\cdot2^{n-1}$
negative_passages.docid: 110262
negative_passages.text: Finding a closed formula for $1\cdot2\cdot3\cdots k +\dots + n(n+1)(n+2)\cdots(k+n-1)$
negative_passages.docid: 19581
negative_passages.text: $\sum_{k=0}^n (-1)^k \binom{n}{k}^2$ and $\sum_{k=0}^n k \binom{n}{k}^2$
negative_passages.docid: 7302
negative_passages.text: $\sum k! = 1! +2! +3! + \cdots + n!$ ,is there a generic formula for this?
negative_passages.docid: 15932
negative_passages.text: How to simplify the summation kk! without using induction?
negative_passages.docid: 18814
negative_passages.text: Sum of the series $1+\frac{1\cdot 3}{6}+\frac{1\cdot3\cdot5}{6\cdot8}+\cdots$
negative_passages.docid: 124229
negative_passages.text: Simplify $\sum_{k=0}^{\infty} x^ky^{\frac{k(k+1)}{2}}$