a(n) = (32*n^3 - 2*n)/3.

Terms

a(0) =0a(1) =10a(2) =84a(3) =286a(4) =680a(5) =1330a(6) =2300a(7) =3654a(8) =5456a(9) =7770a(10) =10660a(11) =14190a(12) =18424a(13) =23426a(14) =29260a(15) =35990a(16) =43680a(17) =52394a(18) =62196a(19) =73150a(20) =85320a(21) =98770a(22) =113564a(23) =129766a(24) =147440a(25) =166650a(26) =187460a(27) =209934a(28) =234136a(29) =260130