523770

Appears in sequences

• Number of 2n-bead balanced binary necklaces of fundamental period 2n, equivalent to reversed complement; also Dirichlet convolution of b_n=2^(n-1) with mu(n); also number of components of Mandelbrot set corresponding to Julia sets with an attractive n-cycle.at n=19A000740
• Number of primitive (aperiodic) word structures of length n which contain exactly two different symbols.at n=19A056278
• Number of primitive (aperiodic) palindromic structures of length n using a maximum of two different symbols.at n=40A056476
• Number of primitive (aperiodic) palindromic structures using exactly two different symbols.at n=40A056481