The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 3 |
| 2 | 18 |
| 3 | 74 |
| 4 | 299 |
| 5 | 1197 |
| 6 | 4785 |
| 7 | 19130 |
| 8 | 76499 |
| 9 | 305959 |
| 10 | 1223777 |
| 11 | 4895020 |
| 12 | 19579955 |
| 13 | 78319649 |
| 14 | 313278369 |
| 15 | 1253113182 |
| 16 | 5012452355 |
| 17 | 20049808955 |
| 18 | 80199235249 |
| 19 | 320796940304 |
| 20 | 1283187760387 |
| 21 | 5132751040565 |
| 22 | 20531004161105 |
| 23 | 82124016643074 |
[3,18,74,299,1197,4785,19130,76499,305959,1223777, 4895020,19579955,78319649,313278369,1253113182, 5012452355,20049808955,80199235249,320796940304, 1283187760387,5132751040565,20531004161105, 82124016643074] |