6 times octagonal numbers: a(n) = 6*n*(3*n-2).

Terms

a(0) =0a(1) =6a(2) =48a(3) =126a(4) =240a(5) =390a(6) =576a(7) =798a(8) =1056a(9) =1350a(10) =1680a(11) =2046a(12) =2448a(13) =2886a(14) =3360a(15) =3870a(16) =4416a(17) =4998a(18) =5616a(19) =6270a(20) =6960a(21) =7686a(22) =8448a(23) =9246a(24) =10080a(25) =10950a(26) =11856a(27) =12798a(28) =13776a(29) =14790