a(n) = n*(2 + 5*n).

Terms

a(0) =0a(1) =7a(2) =24a(3) =51a(4) =88a(5) =135a(6) =192a(7) =259a(8) =336a(9) =423a(10) =520a(11) =627a(12) =744a(13) =871a(14) =1008a(15) =1155a(16) =1312a(17) =1479a(18) =1656a(19) =1843a(20) =2040a(21) =2247a(22) =2464a(23) =2691a(24) =2928a(25) =3175a(26) =3432a(27) =3699a(28) =3976a(29) =4263