Triangle read by rows: number of heapable permutations of length n that contain the number 2 at position k (positions starting from 0).

A390377

Triangle read by rows: number of heapable permutations of length n that contain the number 2 at position k (positions starting from 0).

Terms

    a(0) =0a(1) =0a(2) =1a(3) =0a(4) =1a(5) =1a(6) =0a(7) =2a(8) =2a(9) =1a(10) =0a(11) =6a(12) =6a(13) =3a(14) =2a(15) =0a(16) =23a(17) =23a(18) =12a(19) =8a(20) =5a(21) =0a(22) =109a(23) =109a(24) =59a(25) =40a(26) =25a(27) =17a(28) =0a(29) =613

External references