Number of weak peaks in all Motzkin paths of length n. A weak peak of a Motzkin path is a vertex on the top of a hump. A hump is an upstep followed by 0 or more flatsteps followed by a downstep. For example, the Motzkin path u*duu*h*h*dd, where u=(1,1), h=(1,0), d(1,-1), has 4 weak peaks (shown by the stars).
A247287
Number of weak peaks in all Motzkin paths of length n. A weak peak of a Motzkin path is a vertex on the top of a hump. A hump is an upstep followed by 0 or more flatsteps followed by a downstep. For example, the Motzkin path u*duu*h*h*dd, where u=(1,1), h=(1,0), d(1,-1), has 4 weak peaks (shown by the stars).
Terms
- a(0) =0a(1) =0a(2) =1a(3) =4a(4) =13a(5) =38a(6) =108a(7) =304a(8) =857a(9) =2426a(10) =6902a(11) =19728a(12) =56622a(13) =163092a(14) =471205a(15) =1365008a(16) =3963321a(17) =11530786a(18) =33607190a(19) =98105616a(20) =286795300a(21) =839470664a(22) =2460038427a(23) =7216652488a(24) =21190820678a(25) =62279238828a(26) =183185851903a(27) =539220930004
External references
- oeis: A247287