A332762 Square array T(n,k), n >= 0, k >= 2, read by antidiagonals, where T(n,k) is the number of permutations of {k 1's, k 2's, ..., k n's} with the property that j's are equally spaced for j=1..n and the interval of j+1 is less than or equal to the interval of j for j=1..n-1.

1, 1, 1, 1, 1, 5, 1, 1, 4, 33, 1, 1, 4, 18, 329, 1, 1, 4, 16, 124, 3825, 1, 1, 4, 16, 110, 738, 57293, 1, 1, 4, 16, 104, 544, 7464, 977581, 1, 1, 4, 16, 104, 508, 5444, 55890, 19619645, 1, 1, 4, 16, 104, 484, 5136, 32520, 668778, 442155529

Offset

0,6

Links

Table of n, a(n) for n=0..54.

Example

Square array begins:
      1,    1,    1,    1,    1, ...
      1,    1,    1,    1,    1, ...
      5,    4,    4,    4,    4, ...
     33,   18,   16,   16,   16, ...
    329,  124,  110,  104,  104, ...
   3825,  738,  544,  508,  484, ...
  57293, 7464, 5444, 5136, 4968, ...

Crossrefs

Columns k=2..5 give A322178, A332748, A332752, A332773.

T(n,n) gives A332784.

T(n,n+1) gives A332783.

Sequence in context: A179773 A244977 A071170 * A108691 A010333 A378898

Adjacent sequences: A332759 A332760 A332761 * A332763 A332764 A332765

Keyword

nonn,tabl

Author

Seiichi Manyama, Feb 22 2020

Status

approved