The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 2 |
| 3 | 7 |
| 4 | 14 |
| 5 | 37 |
| 6 | 100 |
| 7 | 271 |
| 8 | 742 |
| 9 | 2054 |
| 10 | 5813 |
| 11 | 16507 |
| 12 | 47501 |
| 13 | 137306 |
| 14 | 399685 |
| 15 | 1169789 |
| 16 | 3438915 |
| 17 | 10153559 |
| 18 | 30083443 |
| 19 | 89426830 |
| 20 | 266598341 |
| 21 | 796863253 |
| 22 | 2387439540 |
| 23 | 7168302094 |
| 24 | 21565117858 |
| 25 | 64993345011 |
| 26 | 196202749033 |
| 27 | 593205591259 |
| 28 | 1796057856430 |
| 29 | 5445108651668 |
| 30 | 16528162238845 |
[2,2,7,14,37,100,271,742,2054,5813,16507,47501, 137306,399685,1169789,3438915,10153559,30083443, 89426830,266598341,796863253,2387439540, 7168302094,21565117858,64993345011,196202749033, 593205591259,1796057856430,5445108651668, 16528162238845] |