The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 6 |
| 4 | 16 |
| 5 | 40 |
| 6 | 96 |
| 7 | 240 |
| 8 | 608 |
| 9 | 1536 |
| 10 | 3840 |
| 11 | 9600 |
| 12 | 24064 |
| 13 | 60416 |
| 14 | 151552 |
| 15 | 379904 |
| 16 | 952320 |
| 17 | 2387968 |
| 18 | 5988352 |
| 19 | 15015936 |
| 20 | 37650432 |
| 21 | 94404608 |
| 22 | 236716032 |
| 23 | 593559552 |
| 24 | 1488322560 |
| 25 | 3731881984 |
| 26 | 9357492224 |
| 27 | 23463460864 |
| 28 | 58833502208 |
| 29 | 147522060288 |
[1,2,6,16,40,96,240,608,1536,3840,9600,24064, 60416,151552,379904,952320,2387968,5988352, 15015936,37650432,94404608,236716032,593559552, 1488322560,3731881984,9357492224,23463460864, 58833502208,147522060288] |