Group the natural numbers such that the product of the terms of the n-th group is divisible by n!: (1), (2), (3, 4), (5, 6, 7, 8), (9, 10, 11, 12), (13, 14, 15, 16, 17, 18), (19, 20, 21, 22, 23, 24), ... Sequence contains the product of the terms of the n-th group divided by n!. a(n) = A085912(n)/(n!).