21539

Appears in sequences

• Numbers k such that k^2 and k^3 have the same set of digits.at n=27A029797
• a(n) = Sum_{i=0..floor(n/2)} A047072(i, n-2*i).at n=24A047079
• a(n)=Sum{T(n,j): j=1,2,...,n}, array T given by A048201.at n=30A048209
• Row sums of A103441. Number of two-colored bracelets of n beads with different sets of distances among the white beads.at n=18A103442
• a(n) = a(n-1) + Sum_{k=0..floor(log_2(n-1))} a(2^k), a(1) = 1.at n=32A133147
• Numbers n such that n!8-2 is prime.at n=56A204664
• Numbers which do not reach zero under either of the iterations: x -> floor(sqrt(x)) * (x - floor(sqrt(x))^2) or y -> ceiling(sqrt(y)) * (ceiling(sqrt(y))^2 - y).at n=27A219963