The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 23 |
| 3 | 148 |
| 4 | 1131 |
| 5 | 8127 |
| 6 | 58091 |
| 7 | 419164 |
| 8 | 3016838 |
| 9 | 21697096 |
| 10 | 156223103 |
| 11 | 1124229264 |
| 12 | 8090787596 |
| 13 | 58233550828 |
| 14 | 419095508303 |
| 15 | 3016219087452 |
| 16 | 21707952324961 |
| 17 | 156230959713801 |
| 18 | 1124391382315226 |
| 19 | 8092241949528463 |
| 20 | 58239664959701115 |
[2,23,148,1131,8127,58091,419164,3016838,21697096, 156223103,1124229264,8090787596,58233550828, 419095508303,3016219087452,21707952324961, 156230959713801,1124391382315226,8092241949528463, 58239664959701115] |