Similar to 2の冪

Fibonacci number

Fibonacci word

Fermat number

Fortunate number

Weird number

Deficient number

Twin prime

Practical number

Blum integer

Friedman number

Brocard's problem

Proth number

Partition function (number theory)

Square-free integer

Square triangular number

Heegner number

Perrin number

Bell number

Pell number

Bernoulli number

Markov number

Mian–Chowla sequence

Mersenne number

Motzkin number

Divisor

Amicable numbers