A026290 - cp's OEIS frontend

A026290 a(n) = number of (s(0), s(1), ..., s(n)) such that every s(i) is an integer, s(0) = 0, s(1) = 1, s(n) = 4, |s(i) - s(i-1)| <= 1 for i >=2, |s(2) - s(1)| = 1, |s(3) - s(2)| = 1 if s(2) = 1. Also a(n) = T(n,n-4), where T is the array in A026268.

n	a(n)
4	1
5	4
6	14
7	46
8	145
9	446
10	1349
11	4034
12	11966
13	35290
14	103642
15	303458
16	886548
17	2585922
18	7534245
19	21934524
20	63826041
21	185668816
22	540034074
23	1570719570
24	4568920029
25	13292253106
26	38679350746
27	112583530784
28	327793747775
29	954702193796

[1, 4, 14, 46, 145, 446, 1349, 4034, 11966, 35290, 103642, 303458, 886548, 2585922, 7534245, 21934524, 63826041, 185668816, 540034074, 1570719570, 4568920029, 13292253106, 38679350746, 112583530784, 327793747775, 954702193796]

cp's OEIS Frontend

A026290 a(n) = number of (s(0), s(1), ..., s(n)) such that every s(i) is an integer, s(0) = 0, s(1) = 1, s(n) = 4, |s(i) - s(i-1)| <= 1 for i >=2, |s(2) - s(1)| = 1, |s(3) - s(2)| = 1 if s(2) = 1. Also a(n) = T(n,n-4), where T is the array in A026268.

Table of values

List of values