ID NAME QUALITY USERS ACC % DIFFICULTY C I
30757 Ada and Carrot   6 116
17
34
32029 Ada and Connections   5 64
26
26
32840 Ada and Digits   14 156
21
18
32949 Ada and Digits 2   4 66
28
28
30739 Ada and Manure   17 279
11
22
30755 Ada and GCD   20 390
28
15
30691 Ada and Diary   1 50
1
1
30737 Ada and Homework   2 54
34
32683 Ada and Kohlrabi   5 54
30
13
32059 Ada and Taxes   15 91
22
22
5151 Alice’s Cube   7 493
25
21
10232 Distinct Primes   83 5565
10
9
4556 Think I will Buy Me a Football Team   28 2118
7
11
5451 Not So Flat After All   9 1098
11
10
13753 Amazing Prime Sequence   60 3214
11
12
30826 Bernoulli numbers   4 6
23
12
31066 Number Breaking   9 541
14
13
21357 Crucial Equation   78 5659
4
9
3505 Prime Number Theorem   24 1477
14
14
9032 Cube Free Numbers   64 4042
12
11
526 Divisors   36 1610
15
14
530 Divisors 2   10 832
14
17
22403 Divisors of factorial   69 1755
14
14
74 Divisor Summation   87 15019
8
10
23963 Easy Factorials   10 111
27
26
4141 Euler Totient Function   142 10705
8
11
22382 Euler Totient Function Depth   23 352
14
15
4942 Integer Factorization (15 digits)   44 3077
11
11
33046 Factorial Modulo Prime   3 15
45
39
25584 Factorial Modulo   25 394
10
15
25067 Fibonacci Polynomial   8 175
10
20
5970 Finding Primes   21 1283
16
15
6264 Rank of a Fraction   4 127
12
34
5978 Frequent Prime Ranges   9 652
13
13
3871 GCD Extreme   74 2102
19
26
41657 GCD Goodness   1 4
26045 GCD OF MATRIX (hard)   3 68
46
30
41507 GCD Product Sum   2 16
1
1
12005 Grass Planting   8 400
34
17
18202 HUGE GCD   17 587
14
13
4164 A conjecture of Paul Erdős   21 1613
16
13
12241 Classification from Erdős and Selfridge   4 22
28
28
27195 Find The Number   7 199
20
17
6221 Increasing Powers of K   4 342
24
34
6256 Inversion Count   521 15450
16
18
40083 Just Primes   10 89
15
17
40084 Just Primes II   5 12
34
28
12183 Help the Commander in Chief   46 893
15
16
34812 Kth Power Summation   5 47
23
17
3442 The last digit   183 26690
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