Sum of the inverse of all positive integers which do not contain the digit 8
75640
Does the harmonic series converge if you throw out the terms containing a $9$?
853
Write down the sum of sum of  sum of digits of $4444^{4444}$
105985
Prove that all even integers $n \neq 2^k$ are expressible as a sum of consecutive positive integers
79895
The modulo operation on negative numbers in Python
35515
Find the number of $(m+n)$ digit binary sequences with $m$ $0$'s and $n$ $1$'s such that no two $1$'s are adjacent
72402
Summation of natural number set with power of $m$
60847
What three odd integers have a sum of 30?
116461
Prove the identity $\sum_{k=0}^{n}(-1)^{k}\binom{n}{k}=0$ using a combinatorial interpretation of the positive and negative terms
18461
Sum of odd Fibonacci Numbers
46158
A positive integer is divisible by $3$ iff 3 divides the sum of its digits
103581
Which positive integers can NOT be written as a sum of consecutive positive integers
100072
Can we add an uncountable number of positive elements, and can this sum be finite?
18064
Sum of reciprocals of numbers with certain terms omitted
68308
A (probably trivial) induction problem: $\sum_2^nk^{-2}\lt1$
96398
An integer $a \pmod m$ has inverse if and only if $\gcd(a,m)=1$?
57846
Multiplicative inverse in $\operatorname{GF}(2^8)$?
72223
Last non Zero digit of a Factorial