a(n) is the sum of all symmetric peaks in the set of flattened Catalan words of length n.

A372884

a(n) is the sum of all symmetric peaks in the set of flattened Catalan words of length n.

Terms

    a(0) =1a(1) =5a(2) =19a(3) =67a(4) =230a(5) =778a(6) =2602a(7) =8618a(8) =28303a(9) =92275a(10) =298949a(11) =963253a(12) =3089020a(13) =9864896a(14) =31388260a(15) =99545572a(16) =314779181a(17) =992765041a(18) =3123577735a(19) =9806581175a(20) =30727287586a(21) =96104495110a(22) =300081382574a(23) =935547839662

External references