| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 4 |
| 5 | 10 |
| 6 | 33 |
| 7 | 105 |
| 8 | 354 |
| 9 | 1214 |
| 10 | 4206 |
| 11 | 14846 |
| 12 | 52750 |
| 13 | 189516 |
| 14 | 686745 |
| 15 | 2506913 |
| 16 | 9211226 |
| 17 | 34036230 |
| 18 | 126426446 |
| 19 | 471769950 |
| 20 | 1767460752 |
| 21 | 6645539212 |
| 22 | 25076120890 |
| 23 | 94937019050 |
| 24 | 360268374124 |
| 25 | 1369645176012 |
| 26 | 5226326126048 |
| 27 | 20039843858208 |
| 28 | 76654036799842 |
| 29 | 290534140464144 |
| 30 | 1123489897863753 |
| 31 | 4582416833711249 |
| 32 | 17212665701732282 |
| 33 | 45565498032190230 |
[1,1,1,4,10,33,105,354,1214,4206,14846,52750, 189516,686745,2506913,9211226,34036230,126426446, 471769950,1767460752,6645539212,25076120890, 94937019050,360268374124,1369645176012, 5226326126048,20039843858208,76654036799842, 290534140464144,1123489897863753,4582416833711249, 17212665701732282,45565498032190230] |