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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 4 |
| 4 | 9 |
| 5 | 25 |
| 6 | 69 |
| 7 | 217 |
| 8 | 745 |
| 9 | 2801 |
| 10 | 11399 |
| 11 | 49859 |
| 12 | 232639 |
| 13 | 1151397 |
| 14 | 6017345 |
| 15 | 33084489 |
| 16 | 190780154 |
| 17 | 1150686536 |
| 18 | 7241926820 |
| 19 | 47455774001 |
| 20 | 323158817943 |
| 21 | 2282794174761 |
| 22 | 16700943712871 |
| 23 | 126356690691651 |
| 24 | 987303203599953 |
| 25 | 7957130740261570 |
| 26 | 66071751478724210 |
| 27 | 564631175841553564 |
| 28 | 4961038559732049506 |
| 29 | 44775183035039043106 |
[1,1,4,9,25,69,217,745,2801,11399,49859,232639, 1151397,6017345,33084489,190780154,1150686536, 7241926820,47455774001,323158817943,2282794174761, 16700943712871,126356690691651,987303203599953, 7957130740261570,66071751478724210, 564631175841553564,4961038559732049506, 44775183035039043106] |