Number of non-necklace compositions of n.

Terms

a(0) =0a(1) =0a(2) =1a(3) =3a(4) =9a(5) =19a(6) =45a(7) =93a(8) =197a(9) =405a(10) =837a(11) =1697a(12) =3465a(13) =7011a(14) =14193a(15) =28653a(16) =57825a(17) =116471a(18) =234549a(19) =471801a(20) =948697a(21) =1906407a(22) =3829581a(23) =7689357a(24) =15435033a(25) =30973005a(26) =62137797a(27) =124630149a(28) =249922665a(29) =501078345