The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 3 |
| 1 | 7 |
| 2 | 18 |
| 3 | 45 |
| 4 | 111 |
| 5 | 272 |
| 6 | 663 |
| 7 | 1611 |
| 8 | 3906 |
| 9 | 9457 |
| 10 | 22875 |
| 11 | 55296 |
| 12 | 133611 |
| 13 | 322751 |
| 14 | 779490 |
| 15 | 1882341 |
| 16 | 4545159 |
| 17 | 10974256 |
| 18 | 26496255 |
| 19 | 63970947 |
| 20 | 154444914 |
| 21 | 372871721 |
| 22 | 900206067 |
| 23 | 2173312512 |
| 24 | 5246877459 |
| 25 | 12667142455 |
| 26 | 30581283762 |
| 27 | 73829906397 |
| 28 | 178241414367 |
| 29 | 430313249360 |
[3,7,18,45,111,272,663,1611,3906,9457,22875,55296, 133611,322751,779490,1882341,4545159,10974256, 26496255,63970947,154444914,372871721,900206067, 2173312512,5246877459,12667142455,30581283762, 73829906397,178241414367,430313249360] |