ID NAME QUALITY USERS ACC % DIFFICULTY C I
30757 Ada and Carrot   6 126
17
34
32029 Ada and Connections   6 70
24
24
32840 Ada and Digits   15 166
20
18
32949 Ada and Digits 2   4 71
28
28
30739 Ada and Manure   17 294
11
22
30755 Ada and GCD   20 418
28
15
30691 Ada and Diary   1 56
1
1
30737 Ada and Homework   3 62
34
34
32683 Ada and Kohlrabi   5 65
30
13
32059 Ada and Taxes   15 104
23
22
5151 Alice’s Cube   8 502
24
21
10232 Distinct Primes   83 5704
10
9
4556 Think I will Buy Me a Football Team   30 2158
7
11
5451 Not So Flat After All   9 1107
11
10
13753 Amazing Prime Sequence   60 3279
11
12
30826 Bernoulli numbers   4 6
23
12
31066 Number Breaking   10 670
13
12
21357 Crucial Equation   79 5892
4
9
3505 Prime Number Theorem   24 1509
14
14
9032 Cube Free Numbers   64 4097
12
11
526 Divisors   36 1654
15
14
530 Divisors 2   10 876
14
17
22403 Divisors of factorial   70 1859
14
14
74 Divisor Summation   91 15429
8
10
23963 Easy Factorials   10 114
27
26
4141 Euler Totient Function   143 11174
8
11
22382 Euler Totient Function Depth   23 365
15
16
4942 Integer Factorization (15 digits)   44 3246
11
11
33046 Factorial Modulo Prime   3 24
45
39
25584 Factorial Modulo   25 404
10
15
25067 Fibonacci Polynomial   8 202
10
20
5970 Finding Primes   21 1318
16
15
6264 Rank of a Fraction   4 129
12
34
5978 Frequent Prime Ranges   9 667
13
13
3871 GCD Extreme   76 2340
18
26
41657 GCD Goodness   1 20
17
17
26045 GCD OF MATRIX (hard)   4 101
46
30
41507 GCD Product Sum   3 30
1
23
12005 Grass Planting   8 443
34
17
18202 HUGE GCD   17 647
14
13
4164 A conjecture of Paul Erdős   23 1844
16
14
12241 Classification from Erdős and Selfridge   5 24
28
28
27195 Find The Number   7 208
20
17
6221 Increasing Powers of K   4 349
24
34
6256 Inversion Count   525 16284
16
18
40083 Just Primes   10 103
15
17
40084 Just Primes II   5 19
34
28
12183 Help the Commander in Chief   46 900
15
16
34812 Kth Power Summation   5 53
23
17
3442 The last digit   185 28652
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