n | a(n) |
---|---|
1 | 4 |
2 | 10 |
3 | 20 |
4 | 55 |
5 | 220 |
6 | 1040 |
7 | 5480 |
8 | 31420 |
9 | 190360 |
10 | 1202930 |
11 | 7848720 |
12 | 52543935 |
13 | 359182620 |
14 | 2498614620 |
15 | 17640615900 |
16 | 126142316865 |
17 | 912047139460 |
18 | 6658803466730 |
19 | 49035674140240 |
20 | 363881247076930 |
21 | 2718918248334300 |
22 | 20442286928323170 |
23 | 154564065790535680 |
24 | 1174669811887063830 |
[4,10,20,55,220,1040,5480,31420,190360,1202930, 7848720,52543935,359182620,2498614620,17640615900, 126142316865,912047139460,6658803466730, 49035674140240,363881247076930,2718918248334300, 20442286928323170,154564065790535680, 1174669811887063830] |