MAHMOOD, M. KHALID; AHMAD, FAROOQ. An informal enumeration of squares of 2k using rooted trees arising from congruences. Utilitas Mathematica , [S. l.], v. 105, 2017. Disponível em: https://utilitasmathematica.com/index.php/Index/article/view/1162. Acesso em: 1 may. 2026.