OFFSET
1,5
COMMENTS
When written in the triangle form as in the example below, the k-th entry (k>=1) in row n (n>=1) is the number of Dumont permutations of the first kind of length 2*n that start with k+1. - Alexander Burstein, May 14 2022
LINKS
G. Kreweras, Sur les permutations comptées par les nombres de Genocchi de 1-ière et 2-ième espèce, Europ. J. Comb., vol. 18, pp. 49-58, 1997.
FORMULA
Row sums give A110501.
EXAMPLE
Triangle begins:
1;
1, 1, 1;
3, 3, 5, 3, 3;
17, 17, 31, 25, 31, 17, 17;
...
CROSSREFS
KEYWORD
tabf,nonn,easy
AUTHOR
EXTENSIONS
More terms from Antonio G. Astudillo (afg_astudillo(AT)lycos.com), Mar 22 2003
STATUS
approved