login
A079507
Triangle T(n,k) read by rows; related to number of preorders.
0
1, 1, 4, 4, 1, 15, 63, 96, 48, 1, 44, 468, 1936, 3688, 3264, 1088, 1, 120, 2795, 23990, 98275, 214640, 256720, 158720, 39680
OFFSET
1,3
COMMENTS
Row n has 2n-1 entries.
LINKS
G. Kreweras, Les préordres totaux compatibles avec un ordre partiel, Math. Sci. Humaines No. 53 (1976), 5-30. (The array on page 22.)
G. Kreweras, Les préordres totaux compatibles avec un ordre partiel, Math. Sci. Humaines No. 53 (1976), 5-30. (Annotated scanned copy)
FORMULA
How is this array defined?
EXAMPLE
1; 1,4,4; 1,15,63,96,48; ...
CROSSREFS
Sequence in context: A124028 A123966 A371898 * A098364 A116866 A126280
KEYWORD
nonn,tabf,more
AUTHOR
N. J. A. Sloane, Jan 21 2003
STATUS
approved