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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 1 |
| 5 | 9 |
| 6 | 49 |
| 7 | 225 |
| 8 | 897 |
| 9 | 11025 |
| 10 | 96801 |
| 11 | 893025 |
| 12 | 6803457 |
| 13 | 108056025 |
| 14 | 1275363153 |
| 15 | 18261468225 |
| 16 | 207592347393 |
| 17 | 4108830350625 |
| 18 | 60889593787713 |
| 19 | 1187451971330625 |
| 20 | 17888210916886017 |
| 21 | 428670161650355625 |
| 22 | 7679611833095218545 |
| 23 | 189043541287806830625 |
| 24 | 3530100224793651058305 |
[1,1,1,1,1,9,49,225,897,11025,96801,893025, 6803457,108056025,1275363153,18261468225, 207592347393,4108830350625,60889593787713, 1187451971330625,17888210916886017, 428670161650355625,7679611833095218545, 189043541287806830625,3530100224793651058305] |