[ (phi + sqrt(phi))^n ], phi = (1+sqrt(5))/2.

Terms

a(0) =1a(1) =2a(2) =8a(3) =24a(4) =69a(5) =201a(6) =582a(7) =1683a(8) =4866a(9) =14065a(10) =40649a(11) =117480a(12) =339524a(13) =981243a(14) =2835846a(15) =8195747a(16) =23686148a(17) =68454240a(18) =197836425a(19) =571757881a(20) =1652410946a(21) =4775556267a(22) =13801613767a(23) =39887404081a(24) =115276737285a(25) =333155954000a(26) =962838576968