Number of compositions of n with an odd number of 1's.

Terms

a(0) =1a(1) =0a(2) =3a(3) =2a(4) =10a(5) =12a(6) =36a(7) =56a(8) =136a(9) =240a(10) =528a(11) =992a(12) =2080a(13) =4032a(14) =8256a(15) =16256a(16) =32896a(17) =65280a(18) =131328a(19) =261632a(20) =524800a(21) =1047552a(22) =2098176a(23) =4192256a(24) =8390656a(25) =16773120a(26) =33558528a(27) =67100672a(28) =134225920a(29) =268419072