login
A226439
Number of permutations of {1..n} with fewer than 6 interior elements having values lying between the values of their neighbors.
1
1, 1, 2, 6, 24, 120, 720, 5040, 40318, 362370, 3600306, 38963958, 453658380, 5626972260, 73801171100, 1017828597300, 14699233982370, 221584676368350, 3477976352489742, 56725919426072106, 959792584260031648, 16822545496476258000, 305055135390508456872
OFFSET
0,3
LINKS
Alois P. Heinz, Table of n, a(n) for n = 0..481 (terms n = 1..210 from R. H. Hardin)
EXAMPLE
Some solutions for n=7
..2....1....6....2....2....6....5....2....6....5....1....2....6....4....5....5
..1....2....3....7....3....5....3....5....3....6....7....7....1....7....1....4
..6....7....4....3....4....7....6....6....2....7....4....6....4....1....2....7
..5....4....2....5....7....2....4....4....5....1....3....3....3....2....7....2
..7....3....5....4....1....3....2....1....4....4....6....5....5....6....6....3
..4....5....1....1....5....4....1....3....1....3....2....4....2....5....4....6
..3....6....7....6....6....1....7....7....7....2....5....1....7....3....3....1
CROSSREFS
Column 6 of A226441.
Sequence in context: A152381 A152385 A360384 * A248840 A072131 A230051
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jun 06 2013
EXTENSIONS
a(0)=1 prepended by Alois P. Heinz, Jul 17 2024
STATUS
approved