ElementUI 设置表格翻页的序号递增

<el-table-column type="index" :index="indexMethod" align="center" label="序号" width="55"></el-table-column>

indexMethod(index) {
      let DepmedicalpageNum = this.DepmedicalpageNum; // 当前页码
      let DepmedicalpageSize = this.DepmedicalpageSize; // 每页条数
      return index + 1 + (DepmedicalpageNum - 1) * DepmedicalpageSize; // 返回表格序号
 },