Fibonacci
Intersection
Leap Years
Prime Numbers
Quine
Tongue-twisters
Vampire Numbers
λ
π
23rd
11th
33rd
101st
84th
19th
31st
46th
54th
61st
170th
80th
31st
37th
29th
79th
71st
51st
414th
66th
108th
48th
37th
9th
8th
τ
φ
√2
𝑒