Algebra 1

x y 1 $2^1$-1 2 $2^2$-1 3 $2^3$-1 4 $2^4$-1 5 $2^5$-1 6 $2^6$-1 7 $2^7$-1 The pattern is that the sum of the terms is the same as 2 raised to the power of the value of x (and then subtracting 1).