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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 4 |
| 3 | 24 |
| 4 | 90 |
| 5 | 365 |
| 6 | 1376 |
| 7 | 7365 |
| 8 | 28002 |
| 9 | 121049 |
| 10 | 465004 |
| 11 | 2437089 |
| 12 | 9396986 |
| 13 | 41758527 |
| 14 | 162167568 |
| 15 | 842470494 |
| 16 | 3277804402 |
| 17 | 14798196587 |
| 18 | 57865149612 |
| 19 | 299015494394 |
| 20 | 1170434872374 |
| 21 | 5339682500573 |
| 22 | 20979019813768 |
| 23 | 107997589923134 |
| 24 | 424558473013940 |
| 25 | 1951503161793927 |
| 26 | 7693926097133316 |
[1,4,24,90,365,1376,7365,28002,121049,465004, 2437089,9396986,41758527,162167568,842470494, 3277804402,14798196587,57865149612,299015494394, 1170434872374,5339682500573,20979019813768, 107997589923134,424558473013940,1951503161793927, 7693926097133316] |