The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 19 |
| 2 | 84 |
| 3 | 115 |
| 4 | 242 |
| 5 | 690 |
| 6 | 1922 |
| 7 | 5460 |
| 8 | 15488 |
| 9 | 43792 |
| 10 | 124002 |
| 11 | 351154 |
| 12 | 994050 |
| 13 | 2814300 |
| 14 | 7968032 |
| 15 | 22558752 |
| 16 | 63867602 |
| 17 | 180820962 |
| 18 | 511936002 |
| 19 | 1449380900 |
| 20 | 4103455232 |
| 21 | 11617609120 |
| 22 | 32891508162 |
| 23 | 93121689570 |
| 24 | 263644006658 |
| 25 | 746422898732 |
[19,84,115,242,690,1922,5460,15488,43792,124002, 351154,994050,2814300,7968032,22558752,63867602, 180820962,511936002,1449380900,4103455232, 11617609120,32891508162,93121689570,263644006658, 746422898732] |