Calculated geometrically, if every member of each generation has four sons, then counting from your grandparents, after four generations you would have 87,381 relatives. Try getting out Christmas cards to that many people!
以幾何方式推算，假設每一位長、晚輩都育有四子，那麼從你算起上、下四代的親戚就有八萬七千三百八十一人。