G.f. A(x) satisfies A(x) = 1 / (1 - x - x * A(x^5)).

Terms

a(0) =1a(1) =2a(2) =4a(3) =8a(4) =16a(5) =32a(6) =66a(7) =136a(8) =280a(9) =576a(10) =1184a(11) =2436a(12) =5012a(13) =10312a(14) =21216a(15) =43648a(16) =89800a(17) =184752a(18) =380104a(19) =782016a(20) =1608896a(21) =3310096a(22) =6810096a(23) =14010896a(24) =28825616a(25) =59304992a(26) =122012384a(27) =251024768a(28) =516451136a(29) =1062531712