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| n | a(n) |
|---|---|
| 1 | 4 |
| 2 | 20 |
| 3 | 80 |
| 4 | 320 |
| 5 | 1280 |
| 6 | 5120 |
| 7 | 20480 |
| 8 | 81920 |
| 9 | 327680 |
| 10 | 1310720 |
| 11 | 5242880 |
| 12 | 20971520 |
| 13 | 83886080 |
| 14 | 335544320 |
| 15 | 1342177280 |
| 16 | 5368709120 |
| 17 | 21474836480 |
| 18 | 85899345920 |
| 19 | 343597383680 |
| 20 | 1374389534720 |
| 21 | 5497558138880 |
| 22 | 21990232555520 |
| 23 | 87960930222080 |
| 24 | 351843720888320 |
| 25 | 1407374883553280 |
[4,20,80,320,1280,5120,20480,81920,327680,1310720, 5242880,20971520,83886080,335544320,1342177280, 5368709120,21474836480,85899345920,343597383680, 1374389534720,5497558138880,21990232555520, 87960930222080,351843720888320,1407374883553280] |