G.f. = continued fraction: A(x)=1/(1-x-x/(1-x^2-x^2/(1-x^3-x^3/(1-x^4-x^4/(...))))).

Terms

a(0) =1a(1) =2a(2) =4a(3) =10a(4) =24a(5) =60a(6) =150a(7) =376a(8) =944a(9) =2372a(10) =5962a(11) =14988a(12) =37684a(13) =94752a(14) =238252a(15) =599090a(16) =1506440a(17) =3788036a(18) =9525280a(19) =23952020a(20) =60229184a(21) =151450970a(22) =380835368a(23) =957640640a(24) =2408063340a(25) =6055266600a(26) =15226449480a(27) =38288118984a(28) =96278523274a(29) =242100012876