Sigma or Summation function in Excel

Question

Given a value (in a cell), calculate a formula like this:

Ʃ(3i+1) for i from 0 to the value specified in the cell.

SUM(), SERIESSUM() are not suitable in thi

Answer 1

To leave you all options, just use this:

=SUMPRODUCT(3*(ROW(A1:INDEX(A:A,B1-A1+1))-(1-A1))+1)

A1 is the lower limit and B1 is the upper limit... will also work for ranges like i = -5 to -3 ;)