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.

A209025 Number of n-bead necklaces labeled with numbers -1..1 allowing reversal, with sum zero and first differences in -1..1.

Table of values

n a(n)
1 1
2 1
3 1
4 2
5 2
6 4
7 6
8 13
9 21
10 45
11 83
12 181
13 362
14 794
15 1676
16 3703
17 8049
18 17925
19 39679
20 88980
21 199308
22 449714
23 1015574
24 2303940
25 5234731
26 11931095
27 27239911
28 62337821
29 142894336
30 328168558
31 754815704
32 1738888333
33 4011453913
34 9266702091
35 21433240903
36 49633242760

List of values

[1, 1, 1, 2, 2, 4, 6, 13, 21, 45, 83, 181, 362, 794, 1676, 3703, 8049, 17925, 39679, 88980, 199308, 449714, 1015574, 2303940, 5234731, 11931095, 27239911, 62337821, 142894336, 328168558, 754815704, 1738888333, 4011453913, 9266702091, 21433240903, 49633242760]