A026327 - cp's OEIS frontend

A026327 a(n) = number of (s(0), s(1), ..., s(n)) such that s(i) is a nonnegative integer and |s(i) - s(i-1)| <= 1 for i = 1,2,...,n, s(0) = 2, s(n) = 4. Also a(n) = T(n,n-2), where T is the array in A026323.

n	a(n)
2	1
3	3
4	10
5	30
6	90
7	266
8	783
9	2295
10	6710
11	19580
12	57057
13	166101
14	483210
15	1405080
16	4084590
17	11872494
18	34508997
19	100313635
20	291646580
21	848102640
22	2466916474
23	7177785582
24	20891443950
25	60827142350
26	177167486925
27	516217883571
28	1504692189588

[1, 3, 10, 30, 90, 266, 783, 2295, 6710, 19580, 57057, 166101, 483210, 1405080, 4084590, 11872494, 34508997, 100313635, 291646580, 848102640, 2466916474, 7177785582, 20891443950, 60827142350, 177167486925, 516217883571, 1504692189588]

cp's OEIS Frontend

A026327 a(n) = number of (s(0), s(1), ..., s(n)) such that s(i) is a nonnegative integer and |s(i) - s(i-1)| <= 1 for i = 1,2,...,n, s(0) = 2, s(n) = 4. Also a(n) = T(n,n-2), where T is the array in A026323.

Table of values

List of values