a(n) = n*(2*n + 13).

Terms

a(0) =0a(1) =15a(2) =34a(3) =57a(4) =84a(5) =115a(6) =150a(7) =189a(8) =232a(9) =279a(10) =330a(11) =385a(12) =444a(13) =507a(14) =574a(15) =645a(16) =720a(17) =799a(18) =882a(19) =969a(20) =1060a(21) =1155a(22) =1254a(23) =1357a(24) =1464a(25) =1575a(26) =1690a(27) =1809a(28) =1932a(29) =2059