a(n) = Product_{d|n, d>1} prime(1+(d mod 4)).

Terms

a(0) =1a(1) =5a(2) =7a(3) =10a(4) =3a(5) =175a(6) =7a(7) =20a(8) =21a(9) =75a(10) =7a(11) =700a(12) =3a(13) =175a(14) =147a(15) =40a(16) =3a(17) =2625a(18) =7a(19) =300a(20) =147a(21) =175a(22) =7a(23) =2800a(24) =9a(25) =75a(26) =147a(27) =700a(28) =3a(29) =91875