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.

A309980 Number of binary relations on n unlabeled nodes that are neither reflexive nor antireflexive.

Table of values

n a(n)
1 0
2 4
3 72
4 2608
5 272752
6 93847104
7 110518842048
8 454710381676032
9 6640565658505128832
10 348708024629593894001152
11 66538376166308068986316241408
12 46534722991725338264882258863095808
13 120139253095727581744381043433138973706240
14 1151909524447243687554850690730124812494959992832

List of values

[0, 4, 72, 2608, 272752, 93847104, 110518842048, 454710381676032, 6640565658505128832, 348708024629593894001152, 66538376166308068986316241408, 46534722991725338264882258863095808, 120139253095727581744381043433138973706240, 1151909524447243687554850690730124812494959992832]

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

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