The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 1 |
| 3 | 3 |
| 4 | 10 |
| 5 | 28 |
| 6 | 79 |
| 7 | 216 |
| 8 | 603 |
| 9 | 1702 |
| 10 | 4933 |
| 11 | 14620 |
| 12 | 44287 |
| 13 | 136352 |
| 14 | 424858 |
| 15 | 1334162 |
| 16 | 4211572 |
| 17 | 13344072 |
| 18 | 42412667 |
| 19 | 135217722 |
| 20 | 432483522 |
| 21 | 1387929369 |
| 22 | 4469341807 |
| 23 | 14439523193 |
| 24 | 46795072968 |
| 25 | 152076428228 |
| 26 | 495460089510 |
| 27 | 1617787324674 |
| 28 | 5292984017236 |
| 29 | 17348743335252 |
[1,0,1,3,10,28,79,216,603,1702,4933,14620,44287, 136352,424858,1334162,4211572,13344072,42412667, 135217722,432483522,1387929369,4469341807, 14439523193,46795072968,152076428228,495460089510, 1617787324674,5292984017236,17348743335252] |