A291080 Irregular triangle read by rows: T(n,m) = number of lattice paths of type {A^H}_R terminating at point (n, m).

1, 3, 2, 1, 19, 16, 10, 4, 1, 141, 126, 90, 50, 21, 6, 1, 1107, 1016, 784, 504, 266, 112, 36, 8, 1, 8953, 8350, 6765, 4740, 2850, 1452, 615, 210, 55, 10, 1, 73789, 69576, 58278, 43252, 28314, 16236, 8074, 3432, 1221, 352, 78, 12, 1, 616227, 585690, 502593, 388752, 270270, 168168, 93093, 45474, 19383, 7098, 2184, 546, 105, 14, 1

Offset

0,2

Links

Table of n, a(n) for n=0..63.

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,
3,2,1,
19,16,10,4,1,
141,126,90,50,21,6,1,
1107,1016,784,504,266,112,36,8,1,
8953,8350,6765,4740,2850,1452,615,210,55,10,1,
73789,69576,58278,43252,28314,16236,8074,3432,1221,352,78,12,1,
616227,585690,502593,388752,270270,168168,93093,45474,19383,7098,2184,546,105,14,1,
...

Crossrefs

First column is A082758.

Sequence in context: A129377 A136733 A117269 * A107862 A117265 A107727

Adjacent sequences: A291077 A291078 A291079 * A291081 A291082 A291083

Keyword

nonn,tabf

Author

N. J. A. Sloane, Aug 19 2017

Status

approved