a(n) = 27*n^2 - 51*n + 24, n>=1.

Terms

a(0) =0a(1) =30a(2) =114a(3) =252a(4) =444a(5) =690a(6) =990a(7) =1344a(8) =1752a(9) =2214a(10) =2730a(11) =3300a(12) =3924a(13) =4602a(14) =5334a(15) =6120a(16) =6960a(17) =7854a(18) =8802a(19) =9804a(20) =10860a(21) =11970a(22) =13134a(23) =14352a(24) =15624a(25) =16950a(26) =18330a(27) =19764a(28) =21252a(29) =22794