262440000domain: NAppears in sequencesa(n) = 2^(n - 1)*permanent(M_n)^2 where M_n is the n X n matrix M_n(j, k) = cos(Pi*j*k/n).at n=14A347281Powers k^m, m > 1, where k is an Achilles number that has a primorial kernel but is not a product of primorials.at n=12A389374