Square elements of A046949.

Terms

a(0) =1a(1) =25a(2) =49a(3) =169a(4) =625a(5) =1369a(6) =3025a(7) =7921a(8) =18769a(9) =37249a(10) =208849a(11) =3485689a(12) =4950625a(13) =7756225a(14) =225150025a(15) =48195616225a(16) =264353307409a(17) =453673643809