|
| |
|
|
A338403
|
|
Regular triangle read by rows: T(n,k) is the number of (n,k)-Duck words, for n>=1 and 0<=k<=n-1.
|
|
0
|
|
|
|
1, 2, 3, 5, 23, 14, 14, 131, 233, 84, 42, 664, 2339, 2367, 594, 132, 3166, 18520, 36265, 24714, 4719, 429, 14545, 127511, 408311, 527757, 266219, 40898
(list;
table;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
|
OFFSET
|
1,2
|
|
|
COMMENTS
|
See link for the definition of Duck word.
|
|
|
LINKS
|
Table of n, a(n) for n=1..28.
Ilani Axelrod-Freed, 312-Avoiding Reduced Valid Hook Configurations and Duck Words, arXiv:2010.11834 [math.CO], 2020. See Definition 5.1 p. 11.
|
|
|
EXAMPLE
|
Triangle begins:
1;
2, 3;
5, 23, 14;
14, 131, 233, 84;
42, 664, 2339, 2367, 594;
...
|
|
|
CROSSREFS
|
Cf. A000108 (column 0), A005700 (diagonal), A005789 (row sums), A031970 (column 1).
Sequence in context: A013639 A047995 A244862 * A024782 A024775 A024767
Adjacent sequences: A338400 A338401 A338402 * A338404 A338405 A338406
|
|
|
KEYWORD
|
nonn,tabl,more
|
|
|
AUTHOR
|
Michel Marcus, Oct 24 2020
|
|
|
STATUS
|
approved
|
| |
|
|
