Inverse Moebius transform of the Mersenne numbers: a(n) = Sum_{d|n} (2^d - 1).

Terms

a(0) =1a(1) =4a(2) =8a(3) =19a(4) =32a(5) =74a(6) =128a(7) =274a(8) =519a(9) =1058a(10) =2048a(11) =4184a(12) =8192a(13) =16514a(14) =32806a(15) =65809a(16) =131072a(17) =262728a(18) =524288a(19) =1049648a(20) =2097286a(21) =4196354a(22) =8388608a(23) =16781654a(24) =33554463a(25) =67117058a(26) =134218246a(27) =268451984a(28) =536870912a(29) =1073775718