A026125 - cp's OEIS frontend

A026125 a(n) = number of (s(0),s(1),...,s(n)) such that every s(i) is a nonnegative integer, s(0) = 1, s(n) = 4, |s(1) - s(0)| = 1, |s(i) - s(i-1)| <= 1 for i >= 2. Also a(n) = T(n,n-3), where T is the array in A026120.

n	a(n)
3	1
4	3
5	11
6	35
7	110
8	336
9	1013
10	3021
11	8945
12	26345
13	77297
14	226161
15	660387
16	1925535
17	5608710
18	16325814
19	47500227
20	138168589
21	401865485
22	1168854085
23	3400065944
24	9892187162
25	28787163584
26	83796367200
27	243997380575
28	710704813221
29	2070833535813

[1, 3, 11, 35, 110, 336, 1013, 3021, 8945, 26345, 77297, 226161, 660387, 1925535, 5608710, 16325814, 47500227, 138168589, 401865485, 1168854085, 3400065944, 9892187162, 28787163584, 83796367200, 243997380575, 710704813221, 2070833535813]

cp's OEIS Frontend

A026125 a(n) = number of (s(0),s(1),...,s(n)) such that every s(i) is a nonnegative integer, s(0) = 1, s(n) = 4, |s(1) - s(0)| = 1, |s(i) - s(i-1)| <= 1 for i >= 2. Also a(n) = T(n,n-3), where T is the array in A026120.

Table of values

List of values