a(n) = n*(14*n + 13).

Terms

a(0) =0a(1) =27a(2) =82a(3) =165a(4) =276a(5) =415a(6) =582a(7) =777a(8) =1000a(9) =1251a(10) =1530a(11) =1837a(12) =2172a(13) =2535a(14) =2926a(15) =3345a(16) =3792a(17) =4267a(18) =4770a(19) =5301a(20) =5860a(21) =6447a(22) =7062a(23) =7705a(24) =8376a(25) =9075a(26) =9802a(27) =10557a(28) =11340a(29) =12151