A199895 - cp's OEIS frontend

A199895 Number of -5..5 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	11
3	51
4	351
5	2031
6	13363
7	82555
8	536967
9	3409609
10	22163661
11	142744843
12	930121865
13	6040974735
14	39482258363
15	257848379869
16	1690142722447
17	11081263427471
18	72823380368573
19	478876538926483
20	3154101346620987

[1, 11, 51, 351, 2031, 13363, 82555, 536967, 3409609, 22163661, 142744843, 930121865, 6040974735, 39482258363, 257848379869, 1690142722447, 11081263427471, 72823380368573, 478876538926483, 3154101346620987]

cp's OEIS Frontend

A199895 Number of -5..5 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