static int powerNumbers ( int n ) {
  HashSet < Integer > v = new HashSet < Integer > ( ) ;
  v . add ( 1 ) ;
  for ( int i = 2 ;
  i * i <= n ;
  i ++ ) {
    int j = i * i ;
    v . add ( j ) ;
    while ( j * i <= n ) {
      v . add ( j * i ) ;
      j = j * i ;
    }
  }
  return v . size ( ) ;
}

static int powerNumbers ( int n ) { HashSet < Integer > v = new HashSet < Integer > ( ) ; v . add ( 1 ) ; for ( int i = 2 ; i * i <= n ; i ++ ) { int j = i * i ; v . add ( j ) ; while ( j * i <= n ) { v . add ( j * i ) ; j = j * i ; } } return v . size ( ) ; }
(method_declaration (modifiers) type: (integral_type) name: (identifier) parameters: (formal_parameters (formal_parameter type: (integral_type) name: (identifier))) body: (block (local_variable_declaration type: (generic_type (type_identifier) (type_arguments (type_identifier))) declarator: (variable_declarator name: (identifier) value: (object_creation_expression type: (generic_type (type_identifier) (type_arguments (type_identifier))) arguments: (argument_list)))) (expression_statement (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (decimal_integer_literal)))) (for_statement init: (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) condition: (binary_expression left: (binary_expression left: (identifier) right: (identifier)) right: (identifier)) update: (update_expression (identifier)) body: (block (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (binary_expression left: (identifier) right: (identifier)))) (expression_statement (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier)))) (while_statement condition: (parenthesized_expression (binary_expression left: (binary_expression left: (identifier) right: (identifier)) right: (identifier))) body: (block (expression_statement (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (binary_expression left: (identifier) right: (identifier))))) (expression_statement (assignment_expression left: (identifier) right: (binary_expression left: (identifier) right: (identifier)))))))) (return_statement (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))))