Partial sums of A000918, starting from index 1.

Terms

a(0) =0a(1) =2a(2) =8a(3) =22a(4) =52a(5) =114a(6) =240a(7) =494a(8) =1004a(9) =2026a(10) =4072a(11) =8166a(12) =16356a(13) =32738a(14) =65504a(15) =131038a(16) =262108a(17) =524250a(18) =1048536a(19) =2097110a(20) =4194260a(21) =8388562a(22) =16777168a(23) =33554382a(24) =67108812a(25) =134217674a(26) =268435400a(27) =536870854a(28) =1073741764a(29) =2147483586