Calculate number of total rows when new rows are added at given interval

[dicken]

Hi, I've been trying to write a formula to calculate the number of rows when new rows are inserted at a give interval,

so in this case I have , keeping it simple, 13 rows, and I want to insert 3 rows at every 2nd row,

so ( ( 13 /2 ) * 3 ) + 13 , but I don't want rows added to then end; the best I've come up with so far is this, but are there better ways ?

 =( IF( 13/2 = QUOTIENT(13,2) ,  ( (QUOTIENT(13,2)-1)* 3) + 13  , (QUOTIENT(13,3)*3) + 13 ))   -3,

Richard.

 

[dicken]

Just, to add, see edit option? , the problem is to to deal with extra unwanted rows, so if grouping by 2, then both 13 and 14 want there last insert at
what will be row 27. as this is to used to find the positions of where rows need to be inserted.

 

[Cubist]

Try:

=(QUOTIENT(13,2)-IF(ISODD(13),1,2))*3+13

 

[dicken]

Try:

=(QUOTIENT(13,2)-IF(ISODD(13),1,2))*3+13

had not thought of using is odd thanks,

Richard.