docstr: Returns the number of independent generators of E_n
docstr_tok: ["Returns","the","number","of","independent","generators","of","E_n"]
code: def basis(self):
      """
      Returns the number of independent generators of E_n
      """
  
      n = self.n
      if n == 6:
          return 78
      if n == 7:
          return 133
      if n == 8:
          return 248
  
file_path: sympy/sympy/liealgebras/type_e.py
imports: from .cartan_type import Standard_Cartan
  from sympy.core.backend import eye, Rational
label_desc: Use image node_id 8 for calling the TypeE obj's underlying member method code with example usage: obj.basis() and returns: int, int, int