171874domain: NAppears in sequencesa(n) = 11*5^n-1.at n=6A198770Permutation of natural numbers: a(n) = A243283(A122111((2*n)-1)).at n=50A244984a(n) = Position of 2^n among the numbers which are divisible by the square of their highest noncomposite factor (i.e., the union of {1} and A070003), 0 if not there.at n=26A244986