A291087 Irregular triangle read by rows: T(n,m) = number of lattice paths of type B^Q terminating at point (n, m).

1, 1, 2, 3, 2, 1, 7, 11, 10, 7, 3, 1, 28, 46, 48, 39, 24, 12, 4, 1, 122, 207, 233, 208, 151, 92, 45, 18, 5, 1, 562, 977, 1154, 1099, 880, 606, 356, 179, 74, 25, 6, 1, 2693, 4769, 5826, 5815, 4975, 3726, 2451, 1419, 714, 310, 112, 33, 7, 1, 13288, 23872, 29904, 30926, 27768, 22112, 15736, 10039, 5720, 2898, 1288, 496, 160, 42, 8, 1

Offset

0,3

Links

Table of n, a(n) for n=0..71.

Veronika Irvine, Lace Tessellations: A mathematical model for bobbin lace and an exhaustive combinatorial search for patterns, PhD Dissertation, University of Victoria, 2016.

Example

Triangle begins:
1,1,
2,3,2,1,
7,11,10,7,3,1,
28,46,48,39,24,12,4,1,
122,207,233,208,151,92,45,18,5,1,
562,977,1154,1099,880,606,356,179,74,25,6,1,
2693,4769,5826,5815,4975,3726,2451,1419,714,310,112,33,7,1,
...

Crossrefs

The first two columns are A291091 and A291090.

Sequence in context: A358605 A360026 A062323 * A020858 A090664 A086764

Adjacent sequences: A291084 A291085 A291086 * A291088 A291089 A291090

Keyword

nonn,tabf

Author

N. J. A. Sloane, Aug 19 2017

Status

approved