Entered in A1 & copied down:

=ROW()-ROW(INDEX(A:A,1))+1

would cause no disruption even if row 1 is deleted.

DL wrote:
xforgive the lack of ecel lingo, but...

i'm trying to create a column of sequential numbers. right now i have the
formula a2=a1+1, a3=a2+1, etc. if i delete row 4 (for example), all numbers
downward are in error, since the a4 formula is erased. is there anyway to
delete a row without disrupting the sequence? can they be reformulated
automatically?