Total number of 321 patterns in all heapable permutations of length n.

A392533

Total number of 321 patterns in all heapable permutations of length n.

Terms

    a(0) =0a(1) =0a(2) =0a(3) =0a(4) =0a(5) =3a(6) =40a(7) =480a(8) =5513a(9) =65051a(10) =800679a(11) =10384967a(12) =142357706a(13) =2064273113a(14) =31644682654a(15) =512196648751

External references