a(0)=7, a(n) = 2*a(n-1) + 2^(n-1) for n > 0.

Terms

a(0) =7a(1) =15a(2) =32a(3) =68a(4) =144a(5) =304a(6) =640a(7) =1344a(8) =2816a(9) =5888a(10) =12288a(11) =25600a(12) =53248a(13) =110592a(14) =229376a(15) =475136a(16) =983040a(17) =2031616a(18) =4194304a(19) =8650752a(20) =17825792a(21) =36700160a(22) =75497472a(23) =155189248a(24) =318767104a(25) =654311424a(26) =1342177280a(27) =2751463424a(28) =5637144576