A334519 Triangle read by rows: T(n,k) (1<=k<=n) = number of n X k whirlpool permutations (see A334518).

1, 2, 8, 6, 84, 5904, 24, 1632, 1064304, 2456909824, 120, 51040, 402671760, 15584878111040, 2179875344187129600, 720, 2340480, 273315542400, 217353588326290944, 823110394280028294344640

Offset

1,2

Links

Table of n, a(n) for n=1..20.

D. E. Knuth, Whirlpool Permutations, May 05 2020.

Example

Triangle begins:
    1,
    2,       8,
    6,      84,         5904,
   24,    1632,      1064304,         2456909824,
  120,   51040,    402671760,     15584878111040,      2179875344187129600,
  720, 2340480, 273315542400, 217353588326290944, 823110394280028294344640, ...
  ...

Crossrefs

Columns: A000142, A261683, A334516; main diagonal = A334517.

See also A334518.

Sequence in context: A079538 A098221 A343101 * A009214 A021781 A130820

Adjacent sequences: A334516 A334517 A334518 * A334520 A334521 A334522

Keyword

nonn,tabl,more

Author

N. J. A. Sloane, May 06 2020

Status

approved