Number of steps that touch the x-axis in all peakless Motzkin paths of length n.

Terms

a(0) =1a(1) =2a(2) =5a(3) =12a(4) =27a(5) =62a(6) =144a(7) =336a(8) =790a(9) =1870a(10) =4452a(11) =10656a(12) =25629a(13) =61910a(14) =150145a(15) =365450a(16) =892434a(17) =2185928a(18) =5369097a(19) =13221422a(20) =32634935a(21) =80730942a(22) =200116410a(23) =496992992a(24) =1236482727a(25) =3081389406a(26) =7690966549a(27) =19224282880a(28) =48119034729a(29) =120599916654