n | a(n) |
---|---|
1 | 1 |
2 | 6 |
3 | 21 |
4 | 108 |
5 | 370 |
6 | 1908 |
7 | 6587 |
8 | 34248 |
9 | 119142 |
10 | 623700 |
11 | 2182818 |
12 | 11487528 |
13 | 40391988 |
14 | 213451560 |
15 | 753295635 |
16 | 3993910416 |
17 | 14136717574 |
18 | 75152083716 |
19 | 266650874678 |
20 | 1420670333640 |
21 | 5050926317724 |
22 | 26960309526744 |
23 | 96015725922014 |
[1,6,21,108,370,1908,6587,34248,119142,623700, 2182818,11487528,40391988,213451560,753295635, 3993910416,14136717574,75152083716,266650874678, 1420670333640,5050926317724,26960309526744, 96015725922014] |