2n^4+6n^2+4 = 2(n^2+1)(n^2+2).

Terms

a(0) =12a(1) =60a(2) =220a(3) =612a(4) =1404a(5) =2812a(6) =5100a(7) =8580a(8) =13612a(9) =20604a(10) =30012a(11) =42340a(12) =58140a(13) =78012a(14) =102604a(15) =132612a(16) =168780a(17) =211900a(18) =262812a(19) =322404a(20) =391612a(21) =471420a(22) =562860a(23) =667012a(24) =785004a(25) =918012a(26) =1067260a(27) =1234020a(28) =1419612a(29) =1625404