n | a(n) |
---|---|
1 | 1 |
2 | 1 |
3 | 4 |
4 | 16 |
5 | 74 |
6 | 364 |
7 | 1876 |
8 | 9993 |
9 | 54582 |
10 | 304040 |
11 | 1720576 |
12 | 9864114 |
13 | 57169168 |
14 | 334404892 |
15 | 1971641096 |
16 | 11705119157 |
17 | 69911438676 |
18 | 419798442416 |
19 | 2532791105844 |
20 | 15346498242460 |
21 | 93344296450020 |
22 | 569741502841020 |
23 | 3488539758461880 |
24 | 21422341792366320 |
[1,1,4,16,74,364,1876,9993,54582,304040,1720576, 9864114,57169168,334404892,1971641096,11705119157, 69911438676,419798442416,2532791105844, 15346498242460,93344296450020,569741502841020, 3488539758461880,21422341792366320] |