The number of binary heaps on n elements whose breadth-first search reading word avoids 321.

A246829

The number of binary heaps on n elements whose breadth-first search reading word avoids 321.

Terms

    a(0) =1a(1) =1a(2) =2a(3) =3a(4) =7a(5) =16a(6) =45a(7) =111a(8) =318a(9) =881a(10) =2686a(11) =8033a(12) =25470a(13) =80480a(14) =263977a(15) =862865a(16) =2891344a(17) =9706757a(18) =33178076a(19) =113784968a(20) =395303480a(21) =1379160685a(22) =4859274472a(23) =17195407935a(24) =61310096228a(25) =219520467207a(26) =790749207801

External references