a(n) = prime(n) * prime(2n).

Terms

a(0) =6a(1) =21a(2) =65a(3) =133a(4) =319a(5) =481a(6) =731a(7) =1007a(8) =1403a(9) =2059a(10) =2449a(11) =3293a(12) =4141a(13) =4601a(14) =5311a(15) =6943a(16) =8201a(17) =9211a(18) =10921a(19) =12283a(20) =13213a(21) =15247a(22) =16517a(23) =19847a(24) =22213a(25) =24139a(26) =25853a(27) =28141a(28) =29539a(29) =31753