n | a(n) |
---|---|
0 | 1 |
1 | 2 |
2 | 6 |
3 | 23 |
4 | 106 |
5 | 572 |
6 | 3564 |
7 | 25377 |
8 | 204446 |
9 | 1844876 |
10 | 18465556 |
11 | 203179902 |
12 | 2438366836 |
13 | 31699511768 |
14 | 443795839192 |
15 | 6656947282725 |
16 | 106511191881270 |
17 | 1810690391626380 |
18 | 32592427526913540 |
19 | 619256124778620450 |
20 | 12385122502136529420 |
21 | 260087572569333384840 |
[1,2,6,23,106,572,3564,25377,204446,1844876, 18465556,203179902,2438366836,31699511768, 443795839192,6656947282725,106511191881270, 1810690391626380,32592427526913540, 619256124778620450,12385122502136529420, 260087572569333384840] |