A225879 - cp's OEIS frontend

A225879 Number of n-length words w over ternary alphabet {1,2,3} such that for every prefix z of w we have 0<=#(z,1)-#(z,2)<=2 and 0<=#(z,2)-#(z,3)<=2 and #(z,x) gives the number of occurrences of letter x in z.

n	a(n)
0	1
1	1
2	2
3	3
4	7
5	14
6	23
7	51
8	102
9	167
10	371
11	742
12	1215
13	2699
14	5398
15	8839
16	19635
17	39270
18	64303
19	142843
20	285686
21	467799
22	1039171
23	2078342
24	3403199
25	7559883
26	15119766
27	24757991
28	54997523
29	109995046
30	180112335
31	400102427
32	800204854
33	1310302327
34	2910712035
35	5821424070

[1, 1, 2, 3, 7, 14, 23, 51, 102, 167, 371, 742, 1215, 2699, 5398, 8839, 19635, 39270, 64303, 142843, 285686, 467799, 1039171, 2078342, 3403199, 7559883, 15119766, 24757991, 54997523, 109995046, 180112335, 400102427, 800204854, 1310302327, 2910712035, 5821424070]

cp's OEIS Frontend

A225879 Number of n-length words w over ternary alphabet {1,2,3} such that for every prefix z of w we have 0<=#(z,1)-#(z,2)<=2 and 0<=#(z,2)-#(z,3)<=2 and #(z,x) gives the number of occurrences of letter x in z.

Table of values

List of values