A179957 - cp's OEIS frontend

A179957 Number of permutations of 1..n such that |p(i)-p(i-1)|>= 4 for i>1.

n	a(n)
0	1
1	1
2	0
3	0
4	0
5	0
6	0
7	0
8	2
9	72
10	1496
11	25384
12	399848
13	6231544
14	99133496
15	1634227958
16	28120703888
17	506599465896
18	9562489659952
19	189055933191880
20	3911226769004280
21	84567966329357056

[1, 1, 0, 0, 0, 0, 0, 0, 2, 72, 1496, 25384, 399848, 6231544, 99133496, 1634227958, 28120703888, 506599465896, 9562489659952, 189055933191880, 3911226769004280, 84567966329357056]

cp's OEIS Frontend

A179957 Number of permutations of 1..n such that |p(i)-p(i-1)|>= 4 for i>1.

Table of values

List of values