login
A165960
Number of permutations of length n without modular 3-sequences.
5
1, 1, 2, 3, 20, 100, 612, 4389, 35688, 325395, 3288490, 36489992, 441093864, 5770007009, 81213878830, 1223895060315, 19662509071056, 335472890422812, 6057979285535388, 115434096553014565, 2314691409652237700, 48723117262650147387, 1074208020519710570054
OFFSET
0,3
COMMENTS
Modular 3-sequences are of the following form: i,i+1,i+2, where arithmetic is modulo n.
LINKS
FORMULA
a(n) = n * A165961(n).
EXAMPLE
For n=3 the a(3) = 3 solutions are (0,2,1), (1,0,2) and (2,1,0).
CROSSREFS
KEYWORD
nonn
AUTHOR
Isaac Lambert, Oct 01 2009
EXTENSIONS
a(0)-a(2) and a(15)-a(22) from Alois P. Heinz, Apr 14 2021
STATUS
approved