a(n) = p*(p - 1)*(501*p^3 - 414*p^2 + 111*p - 54)/120, where p = prime(n).

Terms

a(0) =42a(1) =504a(2) =8796a(3) =53298a(4) =566412a(5) =1341756a(6) =5312160a(7) =9373536a(8) =24790458a(9) =80346588a(10) =112613886a(11) =275440284a(12) =462452448a(13) =588037212a(14) =920759046a(15) =1686448764a(16) =2893307844a(17) =3421602972a(18) =5484429720a(19) =7340452434a(20) =8440231968a(21) =12551864598a(22) =16086117120a(23) =22838112000a(24) =35181089856