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.

A262479 Number of ordered pairs (p,q) of permutations of [n] with equal up-down signatures and p(1)=q(1)=2.

Table of values

n a(n)
2 1
3 2
4 8
5 68
6 952
7 19312
8 533544
9 19209584
10 873274112
11 48904686848
12 3307732742656
13 265835173240320
14 25041294346380800
15 2732759857218994176
16 342041866136488863232
17 48672372916773453011968
18 7813786873387535522529280
19 1405550552561695118460387328

List of values

[1, 2, 8, 68, 952, 19312, 533544, 19209584, 873274112, 48904686848, 3307732742656, 265835173240320, 25041294346380800, 2732759857218994176, 342041866136488863232, 48672372916773453011968, 7813786873387535522529280, 1405550552561695118460387328]

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

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