a(n) = (7*n + 6)^2.

Terms

a(0) =36a(1) =169a(2) =400a(3) =729a(4) =1156a(5) =1681a(6) =2304a(7) =3025a(8) =3844a(9) =4761a(10) =5776a(11) =6889a(12) =8100a(13) =9409a(14) =10816a(15) =12321a(16) =13924a(17) =15625a(18) =17424a(19) =19321a(20) =21316a(21) =23409a(22) =25600a(23) =27889a(24) =30276a(25) =32761a(26) =35344a(27) =38025a(28) =40804a(29) =43681