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.

A245857 Number of preferential arrangements of n labeled elements such that the minimal number of elements per rank equals 4.

Table of values

n a(n)
4 1
5 0
6 0
7 0
8 70
9 252
10 420
11 660
12 35640
13 271700
14 1389388
15 5137860
16 79463020
17 905649500
18 7336909980
19 48400150764
20 573924746400
21 7735300382250
22 85942063340210
23 795156908528290
24 9670781421636258
25 143772253669334950
26 1993964186469438950
27 24015169625528033550

List of values

[1, 0, 0, 0, 70, 252, 420, 660, 35640, 271700, 1389388, 5137860, 79463020, 905649500, 7336909980, 48400150764, 573924746400, 7735300382250, 85942063340210, 795156908528290, 9670781421636258, 143772253669334950, 1993964186469438950, 24015169625528033550]

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

Content is available under The OEIS End-User License Agreement.