The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 4 |
| 2 | 6 |
| 3 | 18 |
| 4 | 30 |
| 5 | 198 |
| 6 | 306 |
| 7 | 462 |
| 8 | 702 |
| 9 | 1482 |
| 10 | 2550 |
| 11 | 3330 |
| 12 | 4422 |
| 13 | 5778 |
| 14 | 6102 |
| 15 | 6498 |
| 16 | 9042 |
| 17 | 11178 |
| 18 | 11778 |
| 19 | 14418 |
| 20 | 15498 |
| 21 | 17298 |
| 22 | 17442 |
| 23 | 19458 |
| 24 | 20862 |
| 25 | 21582 |
| 26 | 22878 |
| 27 | 23322 |
| 28 | 23550 |
| 29 | 25230 |
| 30 | 26622 |
| 31 | 26862 |
| 32 | 26910 |
| 33 | 27378 |
| 34 | 30210 |
| 35 | 34542 |
| 36 | 36738 |
| 37 | 38610 |
| 38 | 39006 |
| 39 | 39102 |
| 40 | 40350 |
| 41 | 40662 |
[4,6,18,30,198,306,462,702,1482,2550,3330,4422, 5778,6102,6498,9042,11178,11778,14418,15498,17298, 17442,19458,20862,21582,22878,23322,23550,25230, 26622,26862,26910,27378,30210,34542,36738,38610, 39006,39102,40350,40662] |