So I have managed to find and workout how the following line of formula works but whenever I attempt to add onto it I seem to be scratching my head and can't figure out how to get it to work with another four columns. I have tried IFERROR but then it just comes up ass blank after the first column even when there are different values in the second column.
=IF(SEQUENCE(COUNTA(A:A)+COUNTA(C:C))<COUNTA(A:A)+1,INDEX(A:A,SEQUENCE(COUNTA(A:A)+COUNTA(C:C))),INDEX(C:C,SEQUENCE(COUNTA(A:A)+COUNTA(C:C))-COUNTA(A:A)))