a(n) = (9*n+4)*(9*n+5).

Terms

a(0) =20a(1) =182a(2) =506a(3) =992a(4) =1640a(5) =2450a(6) =3422a(7) =4556a(8) =5852a(9) =7310a(10) =8930a(11) =10712a(12) =12656a(13) =14762a(14) =17030a(15) =19460a(16) =22052a(17) =24806a(18) =27722a(19) =30800a(20) =34040a(21) =37442a(22) =41006a(23) =44732a(24) =48620a(25) =52670a(26) =56882a(27) =61256a(28) =65792a(29) =70490