A199892 - cp's OEIS frontend

A199892 Number of -2..2 arrays x(0..n-1) of n elements with zero sum, and adjacent elements not both strictly positive and not both strictly negative.

n	a(n)
1	1
2	5
3	15
4	49
5	159
6	533
7	1783
8	6027
9	20437
10	69665
11	238191
12	817083
13	2809845
14	9685397
15	33450675
16	115736335
17	401065951
18	1391807783
19	4836111471
20	16823523661
21	58586196339
22	204217367081
23	712482836479
24	2487770630935
25	8693076444331

[1, 5, 15, 49, 159, 533, 1783, 6027, 20437, 69665, 238191, 817083, 2809845, 9685397, 33450675, 115736335, 401065951, 1391807783, 4836111471, 16823523661, 58586196339, 204217367081, 712482836479, 2487770630935, 8693076444331]

cp's OEIS Frontend

A199892 Number of -2..2 arrays x(0..n-1) of n elements with zero sum, and adjacent elements not both strictly positive and not both strictly negative.

Table of values

List of values