The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 4 |
| 5 | 9 |
| 6 | 20 |
| 7 | 48 |
| 8 | 115 |
| 9 | 286 |
| 10 | 719 |
| 11 | 1842 |
| 12 | 4765 |
| 13 | 12484 |
| 14 | 32968 |
| 15 | 87798 |
| 16 | 235346 |
| 17 | 634752 |
| 18 | 1720897 |
| 19 | 4687949 |
| 20 | 12824195 |
| 21 | 35216118 |
| 22 | 97039045 |
| 23 | 268237121 |
| 24 | 743594937 |
| 25 | 2066803841 |
| 26 | 5758576675 |
| 27 | 16080698759 |
| 28 | 44998355630 |
| 29 | 126161517745 |
| 30 | 354354779794 |
| 31 | 996963790045 |
| 32 | 2809334906744 |
| 33 | 7928088014833 |
| 34 | 22404525682620 |
[0,1,1,2,4,9,20,48,115,286,719,1842,4765,12484, 32968,87798,235346,634752,1720897,4687949, 12824195,35216118,97039045,268237121,743594937, 2066803841,5758576675,16080698759,44998355630, 126161517745,354354779794,996963790045, 2809334906744,7928088014833,22404525682620] |