Number of compositions of n such that the smallest part has multiplicity two.

Terms

a(0) =1a(1) =0a(2) =4a(3) =3a(4) =10a(5) =18a(6) =35a(7) =60a(8) =121a(9) =217a(10) =391a(11) =709a(12) =1281a(13) =2283a(14) =4061a(15) =7185a(16) =12680a(17) =22291a(18) =39051a(19) =68191a(20) =118767a(21) =206331a(22) =357596a(23) =618345a(24) =1066983a(25) =1837513a(26) =3158685a(27) =5420335a(28) =9286086a(29) =15884155