a(n) = ((n-th prime)^6-(n-th prime)^3)/2.

Terms

a(0) =28a(1) =351a(2) =7750a(3) =58653a(4) =885115a(5) =2412306a(6) =12066328a(7) =23519511a(8) =74011861a(9) =297399466a(10) =443736945a(11) =1282837878a(12) =2375017660a(13) =3160641771a(14) =5389555753a(15) =11082106126a(16) =21090164131a(17) =25760073690a(18) =45229040703a(19) =64049963005a(20) =75666918636