a(n) = (10*n + 3)^2.

Terms

a(0) =9a(1) =169a(2) =529a(3) =1089a(4) =1849a(5) =2809a(6) =3969a(7) =5329a(8) =6889a(9) =8649a(10) =10609a(11) =12769a(12) =15129a(13) =17689a(14) =20449a(15) =23409a(16) =26569a(17) =29929a(18) =33489a(19) =37249a(20) =41209a(21) =45369a(22) =49729a(23) =54289a(24) =59049a(25) =64009a(26) =69169a(27) =74529a(28) =80089a(29) =85849