The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 7 |
| 2 | 35 |
| 3 | 154 |
| 4 | 588 |
| 5 | 2065 |
| 6 | 6790 |
| 7 | 21071 |
| 8 | 62447 |
| 9 | 177863 |
| 10 | 489279 |
| 11 | 1305402 |
| 12 | 3389603 |
| 13 | 8587999 |
| 14 | 21280436 |
| 15 | 51674728 |
| 16 | 123161500 |
| 17 | 288539664 |
| 18 | 665292642 |
| 19 | 1511359766 |
| 20 | 3386065697 |
| 21 | 7488093282 |
| 22 | 16357998447 |
| 23 | 35324428405 |
| 24 | 75453678433 |
| 25 | 159512035137 |
| 26 | 333918915120 |
| 27 | 692516812176 |
| 28 | 1423479123640 |
[1,7,35,154,588,2065,6790,21071,62447,177863, 489279,1305402,3389603,8587999,21280436,51674728, 123161500,288539664,665292642,1511359766, 3386065697,7488093282,16357998447,35324428405, 75453678433,159512035137,333918915120, 692516812176,1423479123640] |