a(n) = 16*n^2 + 4*n + 1.

Terms

a(0) =1a(1) =21a(2) =73a(3) =157a(4) =273a(5) =421a(6) =601a(7) =813a(8) =1057a(9) =1333a(10) =1641a(11) =1981a(12) =2353a(13) =2757a(14) =3193a(15) =3661a(16) =4161a(17) =4693a(18) =5257a(19) =5853a(20) =6481a(21) =7141a(22) =7833a(23) =8557a(24) =9313a(25) =10101a(26) =10921a(27) =11773a(28) =12657a(29) =13573