Question 1203513
row 1, 16 seats
row 2, {{{16+2}}}
row 3, {{{16+2*2}}}
row 4, {{{16+3*2}}}
nor n, {{{16+2(n-1)}}}


You want sum from n @ 1 through n @ 46, of {{{16+2(n-1)}}}.
Might be easiest to just use (look for it) the formula.