a(n) = ((prime(n))^4-(prime(n))^2)/4.

Terms

a(0) =3a(1) =18a(2) =150a(3) =588a(4) =3630a(5) =7098a(6) =20808a(7) =32490a(8) =69828a(9) =176610a(10) =230640a(11) =468198a(12) =706020a(13) =854238a(14) =1219368a(15) =1971918a(16) =3028470a(17) =3460530a(18) =5036658a(19) =6351660a(20) =7098228a(21) =9735960a(22) =11862858a(23) =15683580a(24) =22129968a(25) =26012550a(26) =28135068a(27) =32767038a(28) =35286570