OFFSET
0,4
REFERENCES
D. E. Knuth, The Art of Computer Programming Vol. 1, p. 238.
LINKS
M. Bousquet-Mélou, Publications de Mireille Bousquet-Mélou
M. Bousquet-Mélou, Sorted or sortable permutations, Discrete Math., 225 (2000), 25-50.
J. West, Sorting twice through a stack, Theoret. Comput. Sci. 117 (1993) 303-313.
CROSSREFS
KEYWORD
nonn,nice
AUTHOR
EXTENSIONS
Prepended a(0)=1 to match offset, added more terms, Joerg Arndt, Jul 01 2014
STATUS
approved