n | a(n) |
---|---|
0 | 1 |
1 | 4 |
2 | 16 |
3 | 60 |
4 | 228 |
5 | 860 |
6 | 3267 |
7 | 12426 |
8 | 47471 |
9 | 181812 |
10 | 698512 |
11 | 2690086 |
12 | 10384712 |
13 | 40170182 |
14 | 155681112 |
15 | 604362074 |
16 | 2349783665 |
17 | 9148780570 |
18 | 35665860725 |
19 | 139202880860 |
20 | 543887439194 |
21 | 2127148912456 |
22 | 8326877989146 |
23 | 32623644335536 |
[1,4,16,60,228,860,3267,12426,47471,181812,698512, 2690086,10384712,40170182,155681112,604362074, 2349783665,9148780570,35665860725,139202880860, 543887439194,2127148912456,8326877989146, 32623644335536] |