a(n) = (1/n) * Product_{k=1..n} radical(k) for n >= 1, a(0) = 1, where radical(n) is the product of distinct prime factors of n, cf. A007947.

A387140

a(n) = (1/n) * Product_{k=1..n} radical(k) for n >= 1, a(0) = 1, where radical(n) is the product of distinct prime factors of n, cf. A007947.

Terms

    a(0) =1a(1) =1a(2) =1a(3) =2a(4) =3a(5) =12a(6) =60a(7) =360a(8) =630a(9) =1680a(10) =15120a(11) =151200a(12) =831600a(13) =9979200a(14) =129729600a(15) =1816214400a(16) =3405402000a(17) =54486432000a(18) =308756448000

External references