The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 3 |
| 2 | 10 |
| 3 | 24 |
| 4 | 52 |
| 5 | 108 |
| 6 | 220 |
| 7 | 444 |
| 8 | 892 |
| 9 | 1788 |
| 10 | 3580 |
| 11 | 7164 |
| 12 | 14332 |
| 13 | 28668 |
| 14 | 57340 |
| 15 | 114684 |
| 16 | 229372 |
| 17 | 458748 |
| 18 | 917500 |
| 19 | 1835004 |
| 20 | 3670012 |
| 21 | 7340028 |
| 22 | 14680060 |
| 23 | 29360124 |
| 24 | 58720252 |
| 25 | 117440508 |
| 26 | 234881020 |
| 27 | 469762044 |
| 28 | 939524092 |
| 29 | 1879048188 |
[0,3,10,24,52,108,220,444,892,1788,3580,7164, 14332,28668,57340,114684,229372,458748,917500, 1835004,3670012,7340028,14680060,29360124, 58720252,117440508,234881020,469762044,939524092, 1879048188] |