The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 4 |
| 2 | 29 |
| 3 | 209 |
| 4 | 1623 |
| 5 | 12413 |
| 6 | 95623 |
| 7 | 736757 |
| 8 | 5678559 |
| 9 | 43771933 |
| 10 | 337417047 |
| 11 | 2601018757 |
| 12 | 20050333455 |
| 13 | 154561132461 |
| 14 | 1191459205767 |
| 15 | 9184555212821 |
| 16 | 70800627012031 |
| 17 | 545778076046781 |
| 18 | 4207218532446903 |
| 19 | 32432024283432101 |
| 20 | 250007502993994607 |
[4,29,209,1623,12413,95623,736757,5678559, 43771933,337417047,2601018757,20050333455, 154561132461,1191459205767,9184555212821, 70800627012031,545778076046781,4207218532446903, 32432024283432101,250007502993994607] |