The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 7 |
| 3 | 47 |
| 4 | 402 |
| 5 | 4569 |
| 6 | 65298 |
| 7 | 1119789 |
| 8 | 22397112 |
| 9 | 511972065 |
| 10 | 13166163630 |
| 11 | 376208954109 |
| 12 | 11824734538620 |
| 13 | 405454640476833 |
| 14 | 15061050695642994 |
| 15 | 602494304797738845 |
| 16 | 25823425094211472272 |
| 17 | 1180601869774944168513 |
| 18 | 57348495330075309426390 |
[0,1,7,47,402,4569,65298,1119789,22397112, 511972065,13166163630,376208954109,11824734538620, 405454640476833,15061050695642994, 602494304797738845,25823425094211472272, 1180601869774944168513,57348495330075309426390] |