a(n) = 19*n*(n+1).

Terms

a(0) =0a(1) =38a(2) =114a(3) =228a(4) =380a(5) =570a(6) =798a(7) =1064a(8) =1368a(9) =1710a(10) =2090a(11) =2508a(12) =2964a(13) =3458a(14) =3990a(15) =4560a(16) =5168a(17) =5814a(18) =6498a(19) =7220a(20) =7980a(21) =8778a(22) =9614a(23) =10488a(24) =11400a(25) =12350a(26) =13338a(27) =14364a(28) =15428a(29) =16530