I even did the math wrong at the end, but the simplest answer still stands as 37.

]]>It’s the simplest answer that works with the sequence.

4×1

5×2

6×3

7×4 +6 = 34

a+bN = answer for row N.

]]>1 + 4 = 5

(1 + 4) + 2 + 5 = 12

(1 + 4 + 2 + 5) + 3 + 6 = 21

(1 + 4 + 2 + 5 + 3 + 6) + 5 + 8 = 34

1 + ! x $ = 5

2 + 2 x 5 = 12

3 + 3 x 6 = 21

5 + 5 x 8 = 45

The second column lists the values n+3.

The third column lists the values (n+2)^2 – 4; it is all squares minus 4. ]]>