OFFSET
0,3
COMMENTS
a(n) is also the number of allowed patterns of length n of the tent map x -> 1-|1-2x| in [0,1].
LINKS
S. Elizalde and Y. Liu, On basic forbidden patterns of functions, Discrete Appl. Math. 159 (2011), 1207-1216.
FORMULA
a(n) = n! - A193285(n).
EXAMPLE
a(3) = 5 because the allowed patterns of length 3 are 123, 132, 213, 231, 312.
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Sergi Elizalde, Jul 20 2011
EXTENSIONS
a(0)=1 prepended by Alois P. Heinz, Mar 02 2020
STATUS
approved