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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 8 |
| 4 | 32 |
| 5 | 184 |
| 6 | 1264 |
| 7 | 9568 |
| 8 | 79232 |
| 9 | 816128 |
| 10 | 8769536 |
| 11 | 101867776 |
| 12 | 1322831872 |
| 13 | 18122579968 |
| 14 | 268425347072 |
| 15 | 4436611211264 |
| 16 | 73309336469504 |
| 17 | 1303024044310528 |
| 18 | 25235367455752192 |
| 19 | 497968598916333568 |
| 20 | 10431118327503650816 |
| 21 | 234674470003955204096 |
| 22 | 5359992446798535852032 |
[1,1,2,8,32,184,1264,9568,79232,816128,8769536, 101867776,1322831872,18122579968,268425347072, 4436611211264,73309336469504,1303024044310528, 25235367455752192,497968598916333568, 10431118327503650816,234674470003955204096, 5359992446798535852032] |