Given the series - 4; 7; 12; 21; 38; .........what is the seventh term?

Answer 1

4 + (2+2^0) = 7
7 + (2 + 2^0 + 2^1) = 12
12 + (2 + 2^0 + 2^1 + 2^2) = 21
21 + (2 + 2^0 + 2^1 + 2^2 + 2^3) = 38
Therefore for nth term we gave
(2 + 2^0 + .... 2^(n-2)) + (2 + 2^0 + .... 2^(n-1))
For n=7 we have
(2 + 2^0 + .... 2^(5)) + (2 + 2^0 + .... 2^(6)) = 65 + 129 = 194.