ID NAME QUALITY USERS ACC % DIFFICULTY C I
30757 Ada and Carrot   5 102
17
34
32029 Ada and Connections   4 53
23
23
32840 Ada and Digits   14 142
21
18
32949 Ada and Digits 2   4 55
28
28
30739 Ada and Manure   17 243
11
22
30755 Ada and GCD   15 325
29
16
30691 Ada and Diary   1 44
1
1
30737 Ada and Homework   1 50
32683 Ada and Kohlrabi   5 48
30
13
32059 Ada and Taxes   15 79
22
22
5151 Alice’s Cube   7 482
26
23
10232 Distinct Primes   81 5297
9
8
4556 Think I will Buy Me a Football Team   28 2074
7
11
5451 Not So Flat After All   9 1091
11
10
13753 Amazing Prime Sequence   60 3100
11
12
30826 Bernoulli numbers   4 6
23
12
31066 Number Breaking   7 415
16
14
21357 Crucial Equation   74 5150
4
9
3505 Prime Number Theorem   19 1431
13
14
9032 Cube Free Numbers   61 3896
12
10
526 Divisors   35 1535
16
14
530 Divisors 2   8 786
15
17
22403 Divisors of factorial   64 1621
14
14
74 Divisor Summation   82 14438
7
10
23963 Easy Factorials   10 105
27
26
4141 Euler Totient Function   133 9825
8
11
22382 Euler Totient Function Depth   21 328
13
15
4942 Integer Factorization (15 digits)   44 2810
11
11
33046 Factorial Modulo Prime   3 14
45
39
25584 Factorial Modulo   24 366
10
15
25067 Fibonacci Polynomial   8 136
10
20
5970 Finding Primes   21 1255
17
15
6264 Rank of a Fraction   4 125
12
34
5978 Frequent Prime Ranges   7 631
14
12
3871 GCD Extreme   68 1705
19
26
26045 GCD OF MATRIX (hard)   2 31
50
17
12005 Grass Planting   6 254
37
17
18202 HUGE GCD   15 541
11
12
4164 A conjecture of Paul Erdős   19 1348
13
13
12241 Classification from Erdős and Selfridge   3 21
26
26
27195 Find The Number   7 193
20
17
6221 Increasing Powers of K   4 336
24
34
6256 Inversion Count   504 13839
16
18
40083 Just Primes   8 64
15
17
40084 Just Primes II   4 9
34
28
12183 Help the Commander in Chief   46 861
15
16
34812 Kth Power Summation   4 39
20
17
3442 The last digit   175 23370
9
8
5971 LCM Sum   69 2511
19
28
9385 Strictly not a Prime   8 349
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