number of positive integers <= 10^n that are divisible by no prime exceeding p: A066343 A100752 A106598 A106600 A107352 A108274 A108275 A108276 A108277
number of syllables to represent n: A002810 , A045736
number of ways the set (1^k, 2^k, ..., n^k) can be partitioned into two sets of equal sums: k=1 A058377 , k=2 A083527 , k=3 A113263 , k=4 A111253 .
number of words to represent n: A001167
number theory, unsolved problems in: see unsolved problems in number theory (selected)
numbers n such that 2^k + n is prime for all k (empty: see A076336 )
numbers n such that n*2^k + 1 is composite for all k: A076336
numbers n such that n*2^k + 1 is prime for all k (empty: see A076336 )
numbers of form k_1 k_2 .. k_n (1/k_1 + .. + 1/k_n), k_i >= 1: A025052 , A027563 , A027564 , A027565 , A027566 , A055745
numbers, automorphic: see automorphic numbers
numbers, Bernoulli: see Bernoulli numbers
numbers, Euler: see Euler numbers
numbers, feral: see wild numbers
numbers, Gaussian, see Gaussian integers
numbers, octal: see octal numbers
numbers, tri-perfect: A005820
numbers, triperfect: A005820
numbers, triply perfect: A005820
numbers, wild: see wild numbers
n^(n+1): A007778
n^(n-1): A000169 *
n^(n-2): A000272 *
n^(n-3): A007830
n^2-n+41 is prime: A002837
n^n: A000312 *, A014566
n^n^...^n, number of distinct values taken by: A002845 , A003018 , A003019
n_3 configurations: see configurations (combinatorial or geometrical)
n_n: A122618