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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 4 |
| 3 | 12 |
| 4 | 38 |
| 5 | 118 |
| 6 | 424 |
| 7 | 1544 |
| 8 | 5668 |
| 9 | 22186 |
| 10 | 86962 |
| 11 | 347260 |
| 12 | 1426428 |
| 13 | 5869950 |
| 14 | 24589692 |
| 15 | 104252754 |
| 16 | 444133962 |
| 17 | 1916625390 |
| 18 | 8318626668 |
| 19 | 36335194794 |
| 20 | 159998657938 |
| 21 | 707382646426 |
| 22 | 3146397539508 |
| 23 | 14064764511358 |
| 24 | 63107673236226 |
| 25 | 284521869849658 |
| 26 | 1287188819030996 |
| 27 | 5843899644335638 |
| 28 | 26625968697335426 |
[1,2,4,12,38,118,424,1544,5668,22186,86962,347260, 1426428,5869950,24589692,104252754,444133962, 1916625390,8318626668,36335194794,159998657938, 707382646426,3146397539508,14064764511358, 63107673236226,284521869849658,1287188819030996, 5843899644335638,26625968697335426] |