1

Sums of squares then sums of cubes then... 
2

Perfect numbers and sums of odd cubes 
3

Odd triangles 
4

Powers of triangular numbers 
5

All the ones 
6

Factors of factors 
7

The powerful six 
8

Square factor sums 
9

Wilson's pattern 
10

37 times 
11

A prime rich formulae 
12

Harmonic numbers and primes 
13

The number 21322314 
14

Pascal's triangle and the Catalan numbers 
15

Reverse decimal repeaters 
16

More prime rich formulae 
17

Square triangular numbers 
18

Chopping for prime numbers 
19

Pythagorean triples 
20

Fangs for the vampire numbers 
21

Division test for elevens 
22

Armstrong numbers 
23

Primes in arithmetic sequence 
24

Sort, reverse and subtract (Kaprekar) 
25

Add and times are the same 
26

This continues or does it? 
27

All nine digits 
28

The largest known prime 
29

Seven multiplications and a bit more 
30

The multiples of root 2 
31

Powerful sums 
32

The first 206 billion decimal places of Pi 
33

Golden primes 
34

The Sieve of Eratosthenes 
35

A primerich decade 
36

Cabalistic Numerology 
37

The 29th February 
38

Fibonacci's Brothers 
39

Square Permutations 
40

The Divided Sum 
41

The Beastly Number 
42

Smith Numbers 
43

Ordered Digital Equations 
44

The Ultimate Palindrome 
45

Square Products Minus 1 
46

Bulgarian Patience 
47

This doesn't continue or does it? 
48

Very Large Number Contest 
49

Repfigits 
50

The Day Formula 
51

Zig Zag Numbers 
52

Counting to Infinity and Beyond 
53

Unrepeatable Digits 
54

Rabbit Numbers 
55

Benjamin Franklin's Magic Square 
56

A Mathematical Limerick 
57

Polygonal Numbers 
58

Morel's Triangle 