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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 15 |
| 3 | 94 |
| 4 | 663 |
| 5 | 5025 |
| 6 | 39970 |
| 7 | 329145 |
| 8 | 2782095 |
| 9 | 23999078 |
| 10 | 210427869 |
| 11 | 1869908364 |
| 12 | 16802935370 |
| 13 | 152425394958 |
| 14 | 1393972037301 |
| 15 | 12838326815582 |
| 16 | 118970843349711 |
| 17 | 1108503805898190 |
| 18 | 10378559702646846 |
| 19 | 97593299922016224 |
| 20 | 921294705307189029 |
[1,3,15,94,663,5025,39970,329145,2782095,23999078, 210427869,1869908364,16802935370,152425394958, 1393972037301,12838326815582,118970843349711, 1108503805898190,10378559702646846, 97593299922016224,921294705307189029] |