Number of returns to the horizontal axis (both from above and below) in all weighted lattice paths in L_n.

A182899

Number of returns to the horizontal axis (both from above and below) in all weighted lattice paths in L_n.

Terms

    a(0) =0a(1) =0a(2) =0a(3) =2a(4) =6a(5) =18a(6) =54a(7) =152a(8) =422a(9) =1160a(10) =3156a(11) =8534a(12) =22968a(13) =61578a(14) =164602a(15) =438930a(16) =1168120a(17) =3103540a(18) =8234122a(19) =21820098a(20) =57762774a(21) =152774358a(22) =403750258a(23) =1066291206a(24) =2814322014a(25) =7423962336a(26) =19574314938a(27) =51587866820a(28) =135905559330a(29) =357908155044

External references