A291081 Irregular triangle read by rows: T(n,m) = number of lattice paths of type A^H terminating at point (n, m).

1, 1, 7, 6, 3, 1, 51, 45, 30, 15, 5, 1, 393, 357, 266, 161, 77, 28, 7, 1, 3139, 2907, 2304, 1554, 882, 414, 156, 45, 9, 1, 25653, 24068, 19855, 14355, 9042, 4917, 2277, 880, 275, 66, 11, 1, 212941, 201643, 171106, 129844, 87802, 52624, 27742, 12727, 5005, 1651, 442, 91, 13, 1

Offset

0,3

Links

Table of n, a(n) for n=0..55.

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,
7,6,3,1,
51,45,30,15,5,1,
393,357,266,161,77,28,7,1,
3139,2907,2304,1554,882,414,156,45,9,1,
25653,24068,19855,14355,9042,4917,2277,880,275,66,11,1,
212941,201643,171106,129844,87802,52624,27742,12727,5005,1651,442,91,13,1,
...

Crossrefs

First column is A273055.

Sequence in context: A086312 A370746 A214280 * A030797 A019908 A021135

Adjacent sequences: A291078 A291079 A291080 * A291082 A291083 A291084

Keyword

nonn,tabf

Author

N. J. A. Sloane, Aug 19 2017

Status

approved