每字母間隔 逐增 1顯示 (13999)

A3 下拉{=IF((SUM(N(A$2:A2<>""))>A$2)+(ROW(A1)<>SUM(ROW(INDIRECT("1:"&SUM(N(A$2:A2<>"")))))),"",CHAR(64+SUM(N(A$2:A2<>""))))

另解=IF(SUMPRODUCT(N(A$2:A2<>""))>A$2,"",IFERROR(CHAR(MATCH(ROW(A1),MMULT(N(ROW($1:$26)>=COLUMN(A:Z)),ROW($1:$26)),)+64),""))