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.

A321275 Sum over all permutations of [n] of the product of the lengths of longest increasing subsequence and longest decreasing subsequence.

Table of values

n a(n)
1 1
2 4
3 22
4 132
5 890
6 6812
7 58422
8 555900
9 5819658
10 66554180
11 825839718
12 11054124886
13 158795559000
14 2437248222710
15 39809464449676
16 689538524084168
17 12625142440334342
18 243656361772961292
19 4943801229819987022
20 105212500452414418118
21 2343513475564027153128

List of values

[1, 4, 22, 132, 890, 6812, 58422, 555900, 5819658, 66554180, 825839718, 11054124886, 158795559000, 2437248222710, 39809464449676, 689538524084168, 12625142440334342, 243656361772961292, 4943801229819987022, 105212500452414418118, 2343513475564027153128]

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

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