G.f.: q-cosh(x,q)^2 - q-sinh(x,q)^2 at q=-x.

Terms

a(0) =1a(1) =0a(2) =1a(3) =2a(4) =3a(5) =6a(6) =10a(7) =16a(8) =28a(9) =48a(10) =79a(11) =130a(12) =215a(13) =356a(14) =587a(15) =960a(16) =1566a(17) =2558a(18) =4176a(19) =6804a(20) =11066a(21) =17978a(22) =29198a(23) =47406a(24) =76916a(25) =124716a(26) =202152a(27) =327600a(28) =530775a(29) =859734