Number of compositions of n with at least one non-contiguous value.

Terms

a(0) =0a(1) =0a(2) =0a(3) =0a(4) =1a(5) =4a(6) =10a(7) =28a(8) =68a(9) =159a(10) =350a(11) =770a(12) =1642a(13) =3468a(14) =7218a(15) =14870a(16) =30463a(17) =62044a(18) =125818a(19) =254302a(20) =512690a(21) =1031284a(22) =2071858a(23) =4157214a(24) =8334742a(25) =16699103a(26) =33442208a(27) =66947772a(28) =133986940a(29) =268107104