The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 0 |
| 2 | 0 |
| 3 | 1 |
| 4 | 2 |
| 5 | 4 |
| 6 | 8 |
| 7 | 15 |
| 8 | 27 |
| 9 | 48 |
| 10 | 84 |
| 11 | 145 |
| 12 | 248 |
| 13 | 421 |
| 14 | 710 |
| 15 | 1191 |
| 16 | 1989 |
| 17 | 3309 |
| 18 | 5487 |
| 19 | 9073 |
| 20 | 14966 |
| 21 | 24634 |
| 22 | 40472 |
| 23 | 66384 |
| 24 | 108729 |
| 25 | 177858 |
| 26 | 290610 |
| 27 | 474364 |
| 28 | 773615 |
| 29 | 1260643 |
| 30 | 2052818 |
| 31 | 3340662 |
| 32 | 5433345 |
| 33 | 8832432 |
| 34 | 14351403 |
| 35 | 23309326 |
| 36 | 37844645 |
| 37 | 61423513 |
| 38 | 99663191 |
| 39 | 161665653 |
[0,0,0,1,2,4,8,15,27,48,84,145,248,421,710,1191, 1989,3309,5487,9073,14966,24634,40472,66384, 108729,177858,290610,474364,773615,1260643, 2052818,3340662,5433345,8832432,14351403,23309326, 37844645,61423513,99663191,161665653] |