a(n) = 100*n^2 - 151*n + 57.

Terms

a(0) =6a(1) =155a(2) =504a(3) =1053a(4) =1802a(5) =2751a(6) =3900a(7) =5249a(8) =6798a(9) =8547a(10) =10496a(11) =12645a(12) =14994a(13) =17543a(14) =20292a(15) =23241a(16) =26390a(17) =29739a(18) =33288a(19) =37037a(20) =40986a(21) =45135a(22) =49484a(23) =54033a(24) =58782a(25) =63731a(26) =68880a(27) =74229a(28) =79778a(29) =85527