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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 13 |
| 2 | 104 |
| 3 | 637 |
| 4 | 3276 |
| 5 | 14820 |
| 6 | 60697 |
| 7 | 229372 |
| 8 | 810654 |
| 9 | 2706366 |
| 10 | 8600501 |
| 11 | 26173966 |
| 12 | 76654656 |
| 13 | 216903064 |
| 14 | 594973106 |
| 15 | 1586553501 |
| 16 | 4122693185 |
| 17 | 10461067253 |
| 18 | 25967050382 |
| 19 | 63154957281 |
| 20 | 150708128116 |
| 21 | 353304272945 |
| 22 | 814564136529 |
| 23 | 1848834255034 |
| 24 | 4134822087942 |
[1,13,104,637,3276,14820,60697,229372,810654, 2706366,8600501,26173966,76654656,216903064, 594973106,1586553501,4122693185,10461067253, 25967050382,63154957281,150708128116,353304272945, 814564136529,1848834255034,4134822087942] |