A259341 Triangle read by rows: number of balanced twills with 2n harnesses and maximum float length k (1 <= k <= n).

1, 1, 1, 1, 1, 1, 1, 3, 2, 1, 1, 4, 5, 2, 1, 1, 9, 13, 8, 3, 1, 1, 14, 33, 22, 11, 3, 1, 1, 30, 91, 77, 38, 15, 4, 1, 1, 53, 250, 246, 137, 54, 19, 4, 1, 1, 114, 719, 852, 501, 222, 79, 24, 5, 1

Offset

1,8

References

J. A. Hoskins, C. E. Praeger and A. P. Street, Balanced twills with bounded float length, Congress. Numerantium, 40 (1983), 77-89.

Links

Table of n, a(n) for n=1..55.

Janet Anne Hoskins, Isonemal arrays and textile computer graphics, Thesis, 1985. See p. 50.

J. A. Hoskins, C. E. Praeger and A. P. Street, Balanced twills with bounded float length, Congress. Numerantium, 40 (1983), 77-89. (Annotated scanned copy)

Example

Triangle begins:
  1;
  1,   1;
  1,   1,   1;
  1,   3,   2,   1;
  1,   4,   5,   2,   1;
  1,   9,  13,   8,   3,   1;
  1,  14,  33,  22,  11,   3,  1;
  1,  30,  91,  77,  38,  15,  4,  1;
  1,  53, 250, 246, 137,  54, 19,  4, 1;
  1, 114, 719, 852, 501, 222, 79, 24, 5, 1;
  ...

Crossrefs

Row sums are A006840.

Sequence in context: A275494 A137683 A329231 * A369589 A350733 A351073

Adjacent sequences: A259338 A259339 A259340 * A259342 A259343 A259344

Keyword

nonn,tabl

Author

N. J. A. Sloane, Jun 27 2015

Status

approved