OFFSET
1,5
COMMENTS
Rows of the array tend to the Catalan sequence, A000108 starting (1, 2, 5, 14, 42, ...).
LINKS
Antonio Bernini, Matteo Cervetti, Luca Ferrari, Einar Steingrimsson, Enumerative combinatorics of intervals in the Dyck pattern poset, arXiv:1910.00299 [math.CO], 2019. See Table 1 p. 4.
FORMULA
EXAMPLE
First few rows of the array:
1, 1, 1, 1, 1, ...
1, 2, 4, 7, 11, ...
1, 2, 5, 13, 31, ...
1, 2, 5, 14, 41, ...
1, 2, 5, 14, 42, ...
...
First few rows of the triangle:
1;
1, 1;
1, 2, 1;
1, 2, 4, 1;
1, 2, 5, 7, 1;
1, 2, 5, 13, 11, 1;
1, 2, 5, 14, 31, 16, 1;
1, 2, 5, 14, 41, 66, 22, 1;
1, 2, 5, 14, 42, 116, 127, 29, 1;
1, 2, 5, 14, 42, 131, 302, 225, 37, 1;
1, 2, 5, 14, 42, 132, 407, 715, 373, 46, 1;
...
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
Gary W. Adamson, Feb 24 2008
EXTENSIONS
More terms from Alois P. Heinz, Nov 28 2021
STATUS
approved