A208880 - cp's OEIS frontend

A208880 Number of words either empty or beginning with the first letter of the cyclic n-ary alphabet, where each letter of the alphabet occurs twice and letters of neighboring word positions are equal or neighbors in the alphabet.

n	a(n)
0	1
1	1
2	3
3	30
4	62
5	114
6	202
7	346
8	582
9	966
10	1590
11	2602
12	4242
13	6898
14	11198
15	18158
16	29422
17	47650
18	77146
19	124874
20	202102
21	327062
22	529254
23	856410
24	1385762
25	2242274
26	3628142
27	5870526
28	9498782
29	15369426
30	24868330
31	40237882
32	65106342
33	105344358
34	170450838
35	275795338

[1, 1, 3, 30, 62, 114, 202, 346, 582, 966, 1590, 2602, 4242, 6898, 11198, 18158, 29422, 47650, 77146, 124874, 202102, 327062, 529254, 856410, 1385762, 2242274, 3628142, 5870526, 9498782, 15369426, 24868330, 40237882, 65106342, 105344358, 170450838, 275795338]

cp's OEIS Frontend

A208880 Number of words either empty or beginning with the first letter of the cyclic n-ary alphabet, where each letter of the alphabet occurs twice and letters of neighboring word positions are equal or neighbors in the alphabet.

Table of values

List of values