a(n) = 1728000*n - 240.

Terms

a(0) =1727760a(1) =3455760a(2) =5183760a(3) =6911760a(4) =8639760a(5) =10367760a(6) =12095760a(7) =13823760a(8) =15551760a(9) =17279760a(10) =19007760a(11) =20735760a(12) =22463760a(13) =24191760a(14) =25919760a(15) =27647760a(16) =29375760a(17) =31103760a(18) =32831760a(19) =34559760a(20) =36287760a(21) =38015760