ID NAME QUALITY USERS ACC % DIFFICULTY C I
30757 Ada and Carrot   6 135
17
34
32029 Ada and Connections   7 76
26
28
32840 Ada and Digits   15 181
20
18
32949 Ada and Digits 2   5 76
30
30
30739 Ada and Manure   18 314
11
22
30755 Ada and GCD   21 453
27
15
30691 Ada and Diary   3 62
9
9
30737 Ada and Homework   5 68
34
28
32683 Ada and Kohlrabi   5 73
30
13
32059 Ada and Taxes   16 112
23
23
5151 Alice’s Cube   8 514
24
21
10232 Distinct Primes   85 5914
10
9
4556 Think I will Buy Me a Football Team   30 2187
7
11
5451 Not So Flat After All   9 1127
11
10
13753 Amazing Prime Sequence   62 3356
10
12
30826 Bernoulli numbers   4 7
23
12
31066 Number Breaking   10 851
13
12
21357 Crucial Equation   80 6365
4
9
3505 Prime Number Theorem   25 1537
14
13
9032 Cube Free Numbers   65 4162
12
11
526 Divisors   38 1708
14
13
530 Divisors 2   10 932
12
16
22403 Divisors of factorial   71 1974
14
14
74 Divisor Summation   94 16668
7
10
23963 Easy Factorials   10 117
27
26
4141 Euler Totient Function   147 11967
8
11
22382 Euler Totient Function Depth   24 394
15
16
4942 Integer Factorization (15 digits)   45 3643
11
11
33046 Factorial Modulo Prime   4 32
46
42
25584 Factorial Modulo   25 424
10
15
25067 Fibonacci Polynomial   8 237
11
19
5970 Finding Primes   22 1343
16
15
6264 Rank of a Fraction   4 131
12
34
5978 Frequent Prime Ranges   10 715
14
14
3871 GCD Extreme   81 3035
19
26
41657 GCD Goodness   2 28
17
26
26045 GCD OF MATRIX (hard)   4 135
42
29
41507 GCD Product Sum   8 50
9
21
12005 Grass Planting   11 600
29
19
18202 HUGE GCD   17 685
14
13
4164 A conjecture of Paul Erdős   24 2619
16
15
12241 Classification from Erdős and Selfridge   5 31
28
28
27195 Find The Number   7 216
20
17
6221 Increasing Powers of K   4 358
24
34
6256 Inversion Count   533 17923
16
18
40083 Just Primes   11 121
15
17
40084 Just Primes II   7 28
34
30
12183 Help the Commander in Chief   46 914
15
16
34812 Kth Power Summation   6 60
25
19
3442 The last digit   190 30009
9
8

#number-theory

The problem involves number theory, a branch of pure mathematics

https://en.wikipedia.org/wiki/Number_theory http://mathworld.wolfram.com/NumberTheory.html http://www.math.brown.edu/~jhs/frintch1ch6.pdf http://www.britannica.com/topic/number-theory