Number of (1,0)-steps at levels 1,3,5,... in all peakless Motzkin paths of length n.

Terms

a(0) =0a(1) =0a(2) =0a(3) =1a(4) =4a(5) =10a(6) =24a(7) =60a(8) =152a(9) =386a(10) =980a(11) =2488a(12) =6324a(13) =16098a(14) =41032a(15) =104711a(16) =267512a(17) =684138a(18) =1751316a(19) =4487217a(20) =11506792a(21) =29530524a(22) =75841152a(23) =194910254a(24) =501234960a(25) =1289755668a(26) =3320603016a(27) =8553723949a(28) =22044934324a(29) =56841474482