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.

A186638 a(0)=a(1)=a(2)=0; thereafter a(n) = n*a(n-1) + n*a(n-2)/(n-2) + (-1)^(n-1)*4/(n-2).

Table of values

n a(n)
0 0
1 0
2 0
3 4
4 14
5 78
6 488
7 3526
8 28858
9 264256
10 2678632
11 29787932
12 360669542
13 4723907966
14 66555492656
15 1003783052878
16 16136592266226
17 275459689319104
18 4976428074043376
19 94860000118416084
20 1902729366895036542
21 40062161968084543054
22 883460565601444487384
23 20363470614798268185558
24 489687069917632739530538
25 12264310955130816605856448

List of values

[0, 0, 0, 4, 14, 78, 488, 3526, 28858, 264256, 2678632, 29787932, 360669542, 4723907966, 66555492656, 1003783052878, 16136592266226, 275459689319104, 4976428074043376, 94860000118416084, 1902729366895036542, 40062161968084543054, 883460565601444487384, 20363470614798268185558, 489687069917632739530538, 12264310955130816605856448]