Number of Motzkin n-paths with an even number of up steps.

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =3a(5) =11a(6) =31a(7) =71a(8) =155a(9) =379a(10) =1051a(11) =2971a(12) =8053a(13) =21165a(14) =56057a(15) =152881a(16) =425491a(17) =1186227a(18) =3287971a(19) =9102787a(20) =25346457a(21) =71111377a(22) =200425149a(23) =565676629a(24) =1597672277a(25) =4520632981a(26) =12827046181a(27) =36493762501a(28) =104027787451a(29) =296947847203