This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
| n | a(n) |
|---|---|
| 1 | 9 |
| 2 | 9 |
| 3 | 18 |
| 4 | 36 |
| 5 | 63 |
| 6 | 108 |
| 7 | 198 |
| 8 | 360 |
| 9 | 648 |
| 10 | 1161 |
| 11 | 2088 |
| 12 | 3762 |
| 13 | 6768 |
| 14 | 12186 |
| 15 | 21933 |
| 16 | 39483 |
| 17 | 71064 |
| 18 | 127917 |
| 19 | 230256 |
| 20 | 414459 |
| 21 | 746028 |
| 22 | 1342845 |
| 23 | 2417121 |
| 24 | 4350816 |
| 25 | 7831476 |
| 26 | 14096655 |
| 27 | 25373979 |
| 28 | 45673164 |
| 29 | 82211688 |
| 30 | 147981042 |
| 31 | 266365872 |
| 32 | 479458575 |
| 33 | 863025435 |
| 34 | 1553445783 |
| 35 | 2796202404 |