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.

A262379 Number of ordered pairs (p,q) of permutations of [2n] with equal up-down signatures and p(1)=q(1)=n.

Table of values

n a(n)
0 1
1 1
2 8
3 852
4 438496
5 678914816
6 2475764410944
7 18237517555977472
8 244043425473888612352
9 5486719044572824902107136
10 195206678980725195413273903104
11 10481263341014180286866656598294528
12 817228517264548077840269973629276061696

List of values

[1, 1, 8, 852, 438496, 678914816, 2475764410944, 18237517555977472, 244043425473888612352, 5486719044572824902107136, 195206678980725195413273903104, 10481263341014180286866656598294528, 817228517264548077840269973629276061696]

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

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