a(n) = Product_{d|n, d>1} prime(1+(d mod 6)).

Terms

a(0) =1a(1) =5a(2) =7a(3) =55a(4) =13a(5) =70a(6) =3a(7) =275a(8) =49a(9) =715a(10) =13a(11) =1540a(12) =3a(13) =75a(14) =637a(15) =3025a(16) =13a(17) =980a(18) =3a(19) =39325a(20) =147a(21) =715a(22) =13a(23) =15400a(24) =39a(25) =75a(26) =343a(27) =9075a(28) =13a(29) =140140