G.f.: (t^5 + 2*t^4 + t^3 + 2*t^2 + t) / (t^6 + t^5 - 2*t^4 - 5*t^3 - 2*t^2 + t + 1).

Terms

a(0) =0a(1) =1a(2) =1a(3) =2a(4) =7a(5) =5a(6) =20a(7) =27a(8) =49a(9) =106a(10) =155a(11) =331a(12) =560a(13) =1013a(14) =1917a(15) =3310a(16) =6223a(17) =11117a(18) =20140a(19) =36899a(20) =66185a(21) =121014a(22) =218791a(23) =396703a(24) =721280a(25) =1305025a(26) =2371433a(27) =4298618a(28) =7796439a(29) =14150029