cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A328693 Number of double palindrome structures of length n using a maximum of four different symbols.

Table of values

n a(n)
0 1
1 1
2 2
3 4
4 10
5 21
6 50
7 99
8 246
9 445
10 1157
11 2047
12 5326
13 9283
14 24453
15 41859
16 110486
17 187851
18 494411
19 834975
20 2190965
21 3680541
22 9626773
23 16101703
24 41973942
25 69956171
26 181823735
27 302099557
28 783084053
29 1297675587
30 3355767395
31 5548173975
32 14317233046
33 23623397329
34 60846853307

List of values

[1, 1, 2, 4, 10, 21, 50, 99, 246, 445, 1157, 2047, 5326, 9283, 24453, 41859, 110486, 187851, 494411, 834975, 2190965, 3680541, 9626773, 16101703, 41973942, 69956171, 181823735, 302099557, 783084053, 1297675587, 3355767395, 5548173975, 14317233046, 23623397329, 60846853307]