Similar to フェルマー数

Powerful number

Central binomial coefficient

Superabundant number

Superperfect number

Harmonic divisor number

Narcissistic number

Power of two

Nontotient

Harshad number

Multiply perfect number

Hyperperfect number

Eighth power

Semiprime

Fortunate number

Weird number

Deficient number

Twin prime

PrimeGrid

Blum integer

Brocard's problem

Proth number

Partition function (number theory)

Square-free integer

Pell number

Bernoulli number

Markov number

Mian–Chowla sequence