n | a(n) |
---|---|
0 | 1 |
1 | 9 |
2 | 51 |
3 | 233 |
4 | 942 |
5 | 3522 |
6 | 12473 |
7 | 42447 |
8 | 140109 |
9 | 451441 |
10 | 1426380 |
11 | 4434420 |
12 | 13599505 |
13 | 41225349 |
14 | 123723351 |
15 | 368080793 |
16 | 1086665562 |
17 | 3186317718 |
18 | 9286256393 |
19 | 26916587307 |
20 | 77634928209 |
21 | 222920650081 |
[1,9,51,233,942,3522,12473,42447,140109,451441, 1426380,4434420,13599505,41225349,123723351, 368080793,1086665562,3186317718,9286256393, 26916587307,77634928209,222920650081] |