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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 4 |
| 4 | 7 |
| 5 | 46 |
| 6 | 121 |
| 7 | 1114 |
| 8 | 3907 |
| 9 | 46246 |
| 10 | 202741 |
| 11 | 2933074 |
| 12 | 15430207 |
| 13 | 263817646 |
| 14 | 1619195761 |
| 15 | 31943268634 |
| 16 | 224061282907 |
| 17 | 5009616448246 |
| 18 | 39531606447181 |
| 19 | 987840438629794 |
| 20 | 8661323866026007 |
| 21 | 239217148602642046 |
| 22 | 2307185279184885001 |
| 23 | 69790939492563608554 |
[1,1,1,4,7,46,121,1114,3907,46246,202741,2933074, 15430207,263817646,1619195761,31943268634, 224061282907,5009616448246,39531606447181, 987840438629794,8661323866026007, 239217148602642046,2307185279184885001, 69790939492563608554] |