a(0) = 33. a(n) = 3*a(n-1) + 2*n + 1 for n >= 1.

Terms

a(0) =33a(1) =102a(2) =311a(3) =940a(4) =2829a(5) =8498a(6) =25507a(7) =76536a(8) =229625a(9) =688894a(10) =2066703a(11) =6200132a(12) =18600421a(13) =55801290a(14) =167403899a(15) =502211728a(16) =1506635217a(17) =4519905686a(18) =13559717095a(19) =40679151324a(20) =122037454013a(21) =366112362082