Number of Carlitz compositions having at least two identical parts.

Terms

a(0) =0a(1) =0a(2) =0a(3) =0a(4) =1a(5) =2a(6) =3a(7) =10a(8) =20a(9) =44a(10) =67a(11) =149a(12) =277a(13) =528a(14) =959a(15) =1673a(16) =3107a(17) =5572a(18) =9992a(19) =17801a(20) =31647a(21) =55379a(22) =98445a(23) =173288a(24) =305355a(25) =536709a(26) =943353a(27) =1655316a(28) =2900221a(29) =5088098