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.

A078698 Number of ways to lace a shoe that has n pairs of eyelets such that each eyelet has at least one direct connection to the opposite side.

Table of values

n a(n)
1 1
2 2
3 20
4 396
5 14976
6 907200
7 79315200
8 9551001600
9 1513528934400
10 305106949324800
11 76296489615360000
12 23175289163980800000
13 8404709419090575360000
14 3587225703492542791680000
15 1779970753996760560435200000
16 1016036270188884847558656000000
17 661106386935312429191528448000000

List of values

[1, 2, 20, 396, 14976, 907200, 79315200, 9551001600, 1513528934400, 305106949324800, 76296489615360000, 23175289163980800000, 8404709419090575360000, 3587225703492542791680000, 1779970753996760560435200000, 1016036270188884847558656000000, 661106386935312429191528448000000]

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

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