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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 90 |
| 3 | 840 |
| 4 | 4410 |
| 5 | 20118 |
| 6 | 64890 |
| 7 | 186168 |
| 8 | 440730 |
| 9 | 972030 |
| 10 | 2094330 |
| 11 | 4013850 |
| 12 | 7512570 |
| 13 | 13279548 |
| 14 | 21906810 |
| 15 | 34902498 |
| 16 | 54772410 |
| 17 | 84444690 |
| 18 | 124785210 |
| 19 | 181983378 |
| 20 | 259292154 |
| 21 | 358930146 |
| 22 | 492406650 |
| 23 | 664548816 |
| 24 | 889272570 |
| 25 | 1186319550 |
| 26 | 1559209530 |
| 27 | 2012668266 |
| 28 | 2568943290 |
| 29 | 3232452450 |
| 30 | 4031692410 |
[0,90,840,4410,20118,64890,186168,440730,972030, 2094330,4013850,7512570,13279548,21906810, 34902498,54772410,84444690,124785210,181983378, 259292154,358930146,492406650,664548816,889272570, 1186319550,1559209530,2012668266,2568943290, 3232452450,4031692410] |