Expansion of g.f. x*(1+x+x^2)/(1-x-x^2).

Terms

a(0) =1a(1) =2a(2) =4a(3) =6a(4) =10a(5) =16a(6) =26a(7) =42a(8) =68a(9) =110a(10) =178a(11) =288a(12) =466a(13) =754a(14) =1220a(15) =1974a(16) =3194a(17) =5168a(18) =8362a(19) =13530a(20) =21892a(21) =35422a(22) =57314a(23) =92736a(24) =150050a(25) =242786a(26) =392836a(27) =635622a(28) =1028458a(29) =1664080