The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 4 |
| 4 | 9 |
| 5 | 18 |
| 6 | 12 |
| 7 | 13 |
| 8 | 34 |
| 9 | 74 |
| 10 | 72 |
| 11 | 259 |
| 12 | 312 |
| 13 | 892 |
| 14 | 167 |
| 15 | 1334 |
| 16 | 1561 |
| 17 | 3326 |
| 18 | 5133 |
| 19 | 12054 |
[1,2,4,9,18,12,13,34,74,72,259,312,892,167,1334, 1561,3326,5133,12054] |