A240610 - cp's OEIS frontend

A240610 Number of n-length words w over a 4-ary alphabet such that w is empty or a prefix z concatenated with letter a_i and i=1 or 0 < #(z,a_{i-1}) >= #(z,a_i), where #(z,a_i) counts the occurrences of the i-th letter in z.

n	a(n)
0	1
1	1
2	2
3	5
4	14
5	45
6	149
7	509
8	1756
9	6082
10	21246
11	74125
12	260940
13	917060
14	3251573
15	11514563
16	41115372
17	146687475
18	527318119
19	1894548198
20	6853413645
21	24782205276
22	90165044683
23	327958242274
24	1199475359682
25	4386106532923
26	16118279172044
27	59223681674225

[1, 1, 2, 5, 14, 45, 149, 509, 1756, 6082, 21246, 74125, 260940, 917060, 3251573, 11514563, 41115372, 146687475, 527318119, 1894548198, 6853413645, 24782205276, 90165044683, 327958242274, 1199475359682, 4386106532923, 16118279172044, 59223681674225]

cp's OEIS Frontend

A240610 Number of n-length words w over a 4-ary alphabet such that w is empty or a prefix z concatenated with letter a_i and i=1 or 0 < #(z,a_{i-1}) >= #(z,a_i), where #(z,a_i) counts the occurrences of the i-th letter in z.

Table of values

List of values