Number of integer compositions of n that are not the first sums of any finite nonnegative sequence.

Terms

a(0) =0a(1) =0a(2) =0a(3) =0a(4) =1a(5) =3a(6) =11a(7) =28a(8) =76a(9) =178a(10) =429a(11) =957a(12) =2167a(13) =4686a(14) =10220a(15) =21640a(16) =46057a(17) =96091a(18) =201123a(19) =415164a(20) =858748a(21) =1758834a(22) =3607109a(23) =7344997a(24) =14969263a(25) =30348574a(26) =61563612a(27) =124403736a(28) =251481889a(29) =506914707