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.

A208538 Number of n-bead necklaces of n colors allowing reversal, with no adjacent beads having the same color.

Table of values

n a(n)
1 1
2 1
3 1
4 21
5 102
6 1505
7 19995
8 365260
9 7456596
10 174489813
11 4545454545
12 130773238871
13 4115123283810
14 140620807064413
15 5185603185296625
16 205262771447683860
17 8680820740569200760
18 390641235316599920745
19 18637772246193096746253
20 939749336469457562916217

List of values

[1, 1, 1, 21, 102, 1505, 19995, 365260, 7456596, 174489813, 4545454545, 130773238871, 4115123283810, 140620807064413, 5185603185296625, 205262771447683860, 8680820740569200760, 390641235316599920745, 18637772246193096746253, 939749336469457562916217]

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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