login

A002424 as a simple table

na(n)
01
1-18
2126
3-420
4630
5-252
6-84
7-72
8-90
9-140
10-252
11-504
12-1092
13-2520
14-6120
15-15504
16-40698
17-110124
18-305900
19-869400
20-2521260
21-7443720
22-22331160
23-67964400
24-209556900
25-653817528
26-2062039896
27-6567978928
28-21111360840

[1,-18,126,-420,630,-252,-84,-72,-90,-140,-252,
 -504,-1092,-2520,-6120,-15504,-40698,-110124,
 -305900,-869400,-2521260,-7443720,-22331160,
 -67964400,-209556900,-653817528,-2062039896,
 -6567978928,-21111360840]