The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 5 |
| 3 | 21 |
| 4 | 70 |
| 5 | 214 |
| 6 | 614 |
| 7 | 1703 |
| 8 | 4619 |
| 9 | 12363 |
| 10 | 32812 |
| 11 | 86636 |
| 12 | 228012 |
| 13 | 598893 |
| 14 | 1571089 |
| 15 | 4118305 |
| 16 | 10790194 |
| 17 | 28262594 |
| 18 | 74014290 |
| 19 | 193807315 |
| 20 | 507451415 |
| 21 | 1328617751 |
| 22 | 3478516440 |
| 23 | 9107117016 |
| 24 | 23843134680 |
| 25 | 62422772569 |
| 26 | 163425968669 |
| 27 | 427856404653 |
[1,5,21,70,214,614,1703,4619,12363,32812,86636, 228012,598893,1571089,4118305,10790194,28262594, 74014290,193807315,507451415,1328617751, 3478516440,9107117016,23843134680,62422772569, 163425968669,427856404653] |