n | a(n) |
---|---|
0 | 1 |
1 | 1 |
2 | 4 |
3 | 12 |
4 | 45 |
5 | 168 |
6 | 663 |
7 | 2667 |
8 | 10982 |
9 | 45925 |
10 | 194732 |
11 | 834912 |
12 | 3614063 |
13 | 15771795 |
14 | 69316740 |
15 | 306534564 |
16 | 1362986799 |
17 | 6089916936 |
18 | 27328613142 |
19 | 123118156260 |
20 | 556626199974 |
21 | 2524659817449 |
22 | 11484671681511 |
23 | 52384730922720 |
24 | 239534402969925 |
25 | 1097805759803893 |
26 | 5042014405418968 |
[1,1,4,12,45,168,663,2667,10982,45925,194732, 834912,3614063,15771795,69316740,306534564, 1362986799,6089916936,27328613142,123118156260, 556626199974,2524659817449,11484671681511, 52384730922720,239534402969925,1097805759803893, 5042014405418968] |