Cayley's formula summation form
123103
Prove recursive formula for number of spanning trees in complete graph.
72402
Summation of natural number set with power of $m$
83229
Nested summations and their relation to binomial coefficients
116491
Closed form for $\sum_{k=0}^{m} {\binom {m}{k}} a^{k} (b+ck)^N$
19633
Closed form for a pair of continued fractions
61871
Formula for the $n$th term of $1, 2, 2, 3, 3, 3, 4, 4 ,4, 4, 5, ...$
97984
Express as sum of powers
114889
Solve summation $\sum_{i=1}^n \lfloor e\cdot i \rfloor $
110262
Finding a closed formula for $1\cdot2\cdot3\cdots k +\dots + n(n+1)(n+2)\cdots(k+n-1)$
33104
Combinatorial Proof with Summation Identity
14884
Compute a sum with partial fraction decomposition and generating functions
94060
Sum of square binomial coefficients
12648
Did I correctly derive this recurrence equation formula
124135
A general formula for $\sum (k-1)(k-2)(k-3)$?
112644
The product of two numbers that can be written as the sum of two squares
135218
Closed Form for Factorial Sum
26491
Sum function of a series