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| n | a(n) |
|---|---|
| 15 | 2 |
| 16 | 28 |
| 17 | 210 |
| 18 | 1158 |
| 19 | 5112 |
| 20 | 19206 |
| 21 | 63494 |
| 22 | 189092 |
| 23 | 516528 |
| 24 | 1310128 |
| 25 | 3119942 |
| 26 | 7027866 |
| 27 | 15082152 |
| 28 | 30994832 |
| 29 | 61292380 |
| 30 | 117063670 |
| 31 | 216690678 |
| 32 | 389814504 |
| 33 | 683256278 |
| 34 | 1169346934 |
| 35 | 1957831816 |
| 36 | 3212249500 |
| 37 | 5172450680 |
| 38 | 8185057350 |
| 39 | 12743907242 |
| 40 | 19544000940 |
| 41 | 29551096298 |
[2,28,210,1158,5112,19206,63494,189092,516528, 1310128,3119942,7027866,15082152,30994832, 61292380,117063670,216690678,389814504,683256278, 1169346934,1957831816,3212249500,5172450680, 8185057350,12743907242,19544000940,29551096298] |