Describe 2^n.

Terms

a(0) =11a(1) =12a(2) =14a(3) =18a(4) =1116a(5) =1312a(6) =1614a(7) =111218a(8) =121516a(9) =151112a(10) =11101214a(11) =12101418a(12) =14101916a(13) =18111912a(14) =1116131814a(15) =1312171618a(16) =16251316a(17) =111311101712a(18) =1216121124a(19) =1512141228