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| n | a(n) |
|---|---|
| 1 | 4 |
| 2 | 6 |
| 3 | 14 |
| 4 | 30 |
| 5 | 40 |
| 6 | 84 |
| 7 | 176 |
| 8 | 234 |
| 9 | 490 |
| 10 | 1026 |
| 11 | 1364 |
| 12 | 2856 |
| 13 | 5980 |
| 14 | 7950 |
| 15 | 16646 |
| 16 | 34854 |
| 17 | 46336 |
| 18 | 97020 |
| 19 | 203144 |
| 20 | 270066 |
| 21 | 565474 |
| 22 | 1184010 |
| 23 | 1574060 |
| 24 | 3295824 |
| 25 | 6900916 |
| 26 | 9174294 |
| 27 | 19209470 |
| 28 | 40221486 |
| 29 | 53471704 |
| 30 | 111960996 |
| 31 | 234428000 |
| 32 | 311655930 |
| 33 | 652556506 |
[4,6,14,30,40,84,176,234,490,1026,1364,2856,5980, 7950,16646,34854,46336,97020,203144,270066,565474, 1184010,1574060,3295824,6900916,9174294,19209470, 40221486,53471704,111960996,234428000,311655930, 652556506] |