old_contents: from django import template
  
  register = template.Library()
  
  
  @register.filter
  def paginate_numbers(numbers, current_page, max_num=15):
      step = (max_num - 1) / 2
      start = numbers.index(current_page) - step
  
      if start < 0:
          end = numbers.index(current_page) + step + abs(start)
          start = 0
      else:
          end = numbers.index(current_page) + step
      return numbers[start:end + 1]
  
new_contents: from django import template
  
  register = template.Library()
  
  
  @register.filter
  def paginate_numbers(numbers, current_page, max_num=13):
      step = (max_num - 1) / 2
      start = numbers.index(current_page) - step
  
      if start < 0:
          end = numbers.index(current_page) + step + abs(start)
          start = 0
      else:
          end = numbers.index(current_page) + step
      return numbers[start:end + 1]
  
subject: switch the default to to 13 values