a(1)=6; if n = Product p_i^e_i, n>1, then a(n) = Product p_{i+1}^e_i * Product p_{i+2}^e_i.

Terms

a(0) =6a(1) =15a(2) =35a(3) =225a(4) =77a(5) =525a(6) =143a(7) =3375a(8) =1225a(9) =1155a(10) =221a(11) =7875a(12) =323a(13) =2145a(14) =2695a(15) =50625a(16) =437a(17) =18375a(18) =667a(19) =17325a(20) =5005a(21) =3315a(22) =899a(23) =118125a(24) =5929a(25) =4845a(26) =42875a(27) =32175a(28) =1147a(29) =40425