A078673 - cp's OEIS frontend

A078673 Number of ways of arranging the numbers 1..n in a circle so that there is no consecutive triple i, i+1, i+2 or i, i-1, i-2 (mod n).

n	a(n)
1	1
2	1
3	0
4	2
5	6
6	38
7	247
8	1831
9	15287
10	142199
11	1459462
12	16395802
13	200200031
14	2640841839
15	37433428955
16	567531704959
17	9165263237530
18	157084952558930
19	2847992358978623
20	54460529906884855
21	1095499061960126311
22	23125162555673245847
23	511150714875199094358

[1, 1, 0, 2, 6, 38, 247, 1831, 15287, 142199, 1459462, 16395802, 200200031, 2640841839, 37433428955, 567531704959, 9165263237530, 157084952558930, 2847992358978623, 54460529906884855, 1095499061960126311, 23125162555673245847, 511150714875199094358]

cp's OEIS Frontend

A078673 Number of ways of arranging the numbers 1..n in a circle so that there is no consecutive triple i, i+1, i+2 or i, i-1, i-2 (mod n).

Table of values

List of values