The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 40 |
| 2 | 1600 |
| 3 | 13230 |
| 4 | 61254 |
| 5 | 206910 |
| 6 | 571350 |
| 7 | 1369900 |
| 8 | 2956980 |
| 9 | 5883084 |
| 10 | 10965220 |
| 11 | 19372210 |
| 12 | 32726250 |
| 13 | 53222130 |
| 14 | 83765514 |
| 15 | 128131680 |
| 16 | 191146120 |
| 17 | 278888400 |
| 18 | 398920680 |
| 19 | 560542294 |
| 20 | 775071790 |
| 21 | 1056157830 |
| 22 | 1420120350 |
| 23 | 1886323380 |
[40,1600,13230,61254,206910,571350,1369900, 2956980,5883084,10965220,19372210,32726250, 53222130,83765514,128131680,191146120,278888400, 398920680,560542294,775071790,1056157830, 1420120350,1886323380] |