a(n) = (prime(n)^6 - prime(n)^2)/15.

Terms

a(0) =4a(1) =48a(2) =1040a(3) =7840a(4) =118096a(5) =321776a(6) =1609152a(7) =3136368a(8) =9869024a(9) =39654832a(10) =59166848a(11) =171048336a(12) =316673504a(13) =421424080a(14) =718614208a(15) =1477623888a(16) =2812035344a(17) =3434691376a(18) =6030558512a(19) =8540018592a(20) =10088948064a(21) =16205829952a(22) =21796024432