187 Infiniteness of non-twin primes. 73 Examples of mathematical discoveries which were kept as a secret 41 Best way to express 2014 38 How can I write the numbers 5 and 7 as some sequence of operations on three 9s? 21 Examples of mathematical results discovered “late”

### Reputation (7,925)

 -4 List of commonly occurring infinite sequences? +60 Two sets having the same subset sums. +10 What is an example of a sequence which “thins out” and is finite? +10 Prime number theorem approximations.

### Questions (30)

 16 $|3^a-2^b|\neq p$, from a contest 12 A different Harmonic series. 10 $n\cdot \phi(n)=m\cdot \phi(m)$ 8 Proof of binomial coefficient formula. 8 Erdős's exercise.

### Tags (107)

 358 elementary-number-theory × 71 88 big-list × 9 262 prime-numbers × 61 83 reference-request × 7 192 prime-twins × 2 73 mathematicians × 2 92 soft-question × 23 62 number-theory × 46 90 math-history × 4 28 diophantine-equations × 4

### Bookmarks (268)

 925 Can I use my powers for good? [closed] 772 How to study math to really understand it and have a healthy lifestyle with free time? [closed] 756 The staircase paradox, or why $\pi\ne4$ 653 Splitting a sandwich and not feeling deceived 570 Why is $1 - \frac{1}{1 - \frac{1}{1 - \ldots}}$ not real?