Digit Factorial Sum?
97900
Project Euler - 34 / Find a mathematical approach for upper bound
18461
Sum of odd Fibonacci Numbers
44111
Find the value of $\sum_{k=1}^{n}k\binom{n}{k}$?
9126
How many bits are in factorial?
11359
Determine the Set of a Sum of Numbers
41840
How do I evaluate this sum(involving the floor function)?
147505
Calculate the last digit of $3^{347}$
67502
Sum of reciprocal prime numbers
853
Write down the sum of sum of  sum of digits of $4444^{4444}$
3128
Why $9$ & $11$ are special in divisibility tests using decimal digit sums? (casting out nines & elevens)
8806
Summation of binomial coefficients
30496
Casting nines and elevens in other bases (radix) and doing check sums for binary
69228
Factorial of 0 - a convenience?
153796
How to define fractional factorials, like 3.6!?
143945
Summation of combination of binomial coefficient
7327
Sum of the digits of the number 2^1000
2137
Find the number of ways to express 1050 as sum of consecutive integers