Number of weighted lattice paths B(n) having no uudd strings.

Terms

a(0) =1a(1) =1a(2) =2a(3) =4a(4) =8a(5) =17a(6) =36a(7) =80a(8) =180a(9) =410a(10) =946a(11) =2203a(12) =5173a(13) =12233a(14) =29108a(15) =69643a(16) =167437a(17) =404311a(18) =980125a(19) =2384441a(20) =5819576a(21) =14245384a(22) =34964611a(23) =86032272a(24) =212172668a(25) =524371704a(26) =1298509438a(27) =3221425567a(28) =8005623916a(29) =19926840746