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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.

A069726 Number of rooted planar bi-Eulerian maps with 2n edges. Bi-Eulerian: all its vertices and faces are of even valency.

Table of values

n a(n)
0 1
1 1
2 6
3 54
4 594
5 7371
6 99144
7 1412802
8 21025818
9 323686935
10 5120138790
11 82812679560
12 1364498150904
13 22839100002036
14 387477144862128
15 6651170184185802
16 115346229450879978
17 2018559015390399615
18 35610482089433479410
19 632770874050702595670
20 11317118106279639106530

List of values

[1, 1, 6, 54, 594, 7371, 99144, 1412802, 21025818, 323686935, 5120138790, 82812679560, 1364498150904, 22839100002036, 387477144862128, 6651170184185802, 115346229450879978, 2018559015390399615, 35610482089433479410, 632770874050702595670, 11317118106279639106530]

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

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