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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 9 |
| 3 | 60 |
| 4 | 370 |
| 5 | 2235 |
| 6 | 13431 |
| 7 | 80614 |
| 8 | 483720 |
| 9 | 2902365 |
| 10 | 17414245 |
| 11 | 104485536 |
| 12 | 626913294 |
| 13 | 3761479855 |
| 14 | 22568879235 |
| 15 | 135413275530 |
| 16 | 812479653316 |
| 17 | 4874877920049 |
| 18 | 29249267520465 |
| 19 | 175495605122980 |
| 20 | 1052973630738090 |
| 21 | 6317841784428771 |
| 22 | 37907050706572879 |
| 23 | 227442304239437550 |
| 24 | 1364653825436625600 |
[1,9,60,370,2235,13431,80614,483720,2902365, 17414245,104485536,626913294,3761479855, 22568879235,135413275530,812479653316, 4874877920049,29249267520465,175495605122980, 1052973630738090,6317841784428771, 37907050706572879,227442304239437550, 1364653825436625600] |