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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 26 |
| 2 | 588 |
| 3 | 5376 |
| 4 | 30660 |
| 5 | 129780 |
| 6 | 446292 |
| 7 | 1315776 |
| 8 | 3444012 |
| 9 | 8198190 |
| 10 | 18058040 |
| 11 | 37285248 |
| 12 | 72882264 |
| 13 | 135925608 |
| 14 | 243374040 |
| 15 | 420468480 |
| 16 | 703858344 |
| 17 | 1145608002 |
| 18 | 1818257364 |
| 19 | 2821132160 |
| 20 | 4288122300 |
| 21 | 6397170780 |
| 22 | 9381740940 |
| 23 | 13544556480 |
| 24 | 19273936500 |
| 25 | 27063076950 |
| 26 | 37532660256 |
[0,26,588,5376,30660,129780,446292,1315776, 3444012,8198190,18058040,37285248,72882264, 135925608,243374040,420468480,703858344, 1145608002,1818257364,2821132160,4288122300, 6397170780,9381740940,13544556480,19273936500, 27063076950,37532660256] |