Number of compositions (ordered partitions) of n into deficient numbers (A005100).

Terms

a(0) =1a(1) =1a(2) =2a(3) =4a(4) =8a(5) =16a(6) =31a(7) =62a(8) =123a(9) =244a(10) =484a(11) =960a(12) =1904a(13) =3777a(14) =7492a(15) =14861a(16) =29478a(17) =58472a(18) =115984a(19) =230064a(20) =456350a(21) =905208a(22) =1795554a(23) =3561628a(24) =7064780a(25) =14013568a(26) =27797058a(27) =55137735a(28) =109370201a(29) =216944729