ID NAME QUALITY USERS ACC % DIFFICULTY C I
30757 Ada and Carrot   5 101
17
34
32029 Ada and Connections   4 53
23
23
32840 Ada and Digits   14 136
21
18
32949 Ada and Digits 2   4 55
28
28
30739 Ada and Manure   16 230
11
22
30755 Ada and GCD   15 294
29
16
30691 Ada and Diary   1 42
1
1
30737 Ada and Homework   1 50
32683 Ada and Kohlrabi   5 46
30
13
32059 Ada and Taxes   14 76
23
23
5151 Alice’s Cube   7 481
26
23
10232 Distinct Primes   78 5093
9
8
4556 Think I will Buy Me a Football Team   28 2057
7
11
5451 Not So Flat After All   9 1086
11
10
13753 Amazing Prime Sequence   54 3013
11
13
30826 Bernoulli numbers   4 6
23
12
31066 Number Breaking   7 361
16
14
21357 Crucial Equation   70 4708
4
9
3505 Prime Number Theorem   17 1390
13
14
9032 Cube Free Numbers   60 3774
12
11
526 Divisors   34 1495
16
14
530 Divisors 2   8 771
15
17
22403 Divisors of factorial   62 1534
14
14
74 Divisor Summation   75 14079
7
10
23963 Easy Factorials   10 105
27
26
4141 Euler Totient Function   129 9365
8
11
22382 Euler Totient Function Depth   20 318
13
14
4942 Integer Factorization (15 digits)   42 2662
11
11
33046 Factorial Modulo Prime   2 12
42
34
25584 Factorial Modulo   23 365
10
15
25067 Fibonacci Polynomial   8 138
10
20
5970 Finding Primes   20 1186
16
14
6264 Rank of a Fraction   4 127
12
34
5978 Frequent Prime Ranges   7 625
14
12
3871 GCD Extreme   64 1528
19
26
26045 GCD OF MATRIX (hard)   2 24
50
17
12005 Grass Planting   6 234
37
17
18202 HUGE GCD   14 530
11
12
4164 A conjecture of Paul Erdős   14 1146
11
11
12241 Classification from Erdős and Selfridge   3 21
26
26
27195 Find The Number   7 192
20
17
6221 Increasing Powers of K   4 329
24
34
6256 Inversion Count   490 13078
16
18
40083 Just Primes   3 13
9
17
40084 Just Primes II   2 2
34
26
12183 Help the Commander in Chief   45 838
15
16
34812 Kth Power Summation   4 37
20
17
3442 The last digit   174 22102
9
8
5971 LCM Sum   67 2342
19
28
9385 Strictly not a Prime   8 343
17
12

#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