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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.

A007139 Number of unlabeled bicolored bipartite graphs on 2n nodes having n nodes of each color with no edges between vertices of the same color and allowing the color classes to be interchanged.

Table of values

n a(n)
0 1
1 2
2 6
3 26
4 192
5 3014
6 127757
7 16853750
8 7343780765
9 10733574184956
10 52867617324773592
11 882178116079222400788
12 50227997322550920824045262
13 9837048598740665027344331562224
14 6681839615514161556535851222043192179
15 15867777966020615016665849049841756464001994

List of values

[1, 2, 6, 26, 192, 3014, 127757, 16853750, 7343780765, 10733574184956, 52867617324773592, 882178116079222400788, 50227997322550920824045262, 9837048598740665027344331562224, 6681839615514161556535851222043192179, 15867777966020615016665849049841756464001994]

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

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