a(n) = 2*n*(2*n-1).

Terms

a(0) =0a(1) =2a(2) =12a(3) =30a(4) =56a(5) =90a(6) =132a(7) =182a(8) =240a(9) =306a(10) =380a(11) =462a(12) =552a(13) =650a(14) =756a(15) =870a(16) =992a(17) =1122a(18) =1260a(19) =1406a(20) =1560a(21) =1722a(22) =1892a(23) =2070a(24) =2256a(25) =2450a(26) =2652a(27) =2862a(28) =3080a(29) =3306