Number of compositions of n with distinct differences up to sign.

Terms

a(0) =1a(1) =1a(2) =2a(3) =3a(4) =6a(5) =9a(6) =12a(7) =23a(8) =38a(9) =61a(10) =78a(11) =135a(12) =194a(13) =315a(14) =454a(15) =699a(16) =982a(17) =1495a(18) =2102a(19) =3085a(20) =4406a(21) =6583a(22) =9048a(23) =13117a(24) =18540a(25) =26399a(26) =36484a(27) =51885a(28) =72498a(29) =100031