Number of lattice paths from (0,0) to the line x+y=n that use the step set {(0,1),(1,0),(2,0),(3,0),...} and never pass below y=x.

A089324

Number of lattice paths from (0,0) to the line x+y=n that use the step set {(0,1),(1,0),(2,0),(3,0),...} and never pass below y=x.

Terms

    a(0) =1a(1) =1a(2) =2a(3) =3a(4) =7a(5) =12a(6) =29a(7) =53a(8) =130a(9) =247a(10) =611a(11) =1192a(12) =2965a(13) =5897a(14) =14726a(15) =29723a(16) =74443a(17) =152020a(18) =381617a(19) =786733a(20) =1978582a(21) =4111295a(22) =10355303a(23) =21661168a(24) =54628201a(25) =114925697a(26) =290148890a(27) =613442227a(28) =1550177791a(29) =3291704108

External references