Number of 3D walks of type bce.

Terms

a(0) =1a(1) =3a(2) =12a(3) =53a(4) =252a(5) =1252a(6) =6416a(7) =33609a(8) =178996a(9) =965660a(10) =5263728a(11) =28936404a(12) =160204336a(13) =892313424a(14) =4995832640a(15) =28096475977a(16) =158638993476a(17) =898844200524