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| n | a(n) |
|---|---|
| 0 | 4 |
| 1 | 12 |
| 2 | 37 |
| 3 | 115 |
| 4 | 358 |
| 5 | 1115 |
| 6 | 3473 |
| 7 | 10818 |
| 8 | 33697 |
| 9 | 104963 |
| 10 | 326950 |
| 11 | 1018419 |
| 12 | 3172281 |
| 13 | 9881362 |
| 14 | 30779529 |
| 15 | 95875387 |
| 16 | 298642966 |
| 17 | 930245227 |
| 18 | 2897627873 |
| 19 | 9025842914 |
| 20 | 28114666162 |
| 21 | 87574585658 |
| 22 | 272786737320 |
| 23 | 849705465331 |
| 24 | 2646753962113 |
| 25 | 8244393877392 |
| 26 | 25680524664755 |
[4,12,37,115,358,1115,3473,10818,33697,104963, 326950,1018419,3172281,9881362,30779529,95875387, 298642966,930245227,2897627873,9025842914, 28114666162,87574585658,272786737320,849705465331, 2646753962113,8244393877392,25680524664755] |