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) |
|---|---|
| 0 | 0 |
| 1 | 3 |
| 2 | 21 |
| 3 | 144 |
| 4 | 987 |
| 5 | 6765 |
| 6 | 46368 |
| 7 | 317811 |
| 8 | 2178309 |
| 9 | 14930352 |
| 10 | 102334155 |
| 11 | 701408733 |
| 12 | 4807526976 |
| 13 | 32951280099 |
| 14 | 225851433717 |
| 15 | 1548008755920 |
| 16 | 10610209857723 |
| 17 | 72723460248141 |
| 18 | 498454011879264 |
| 19 | 3416454622906707 |
| 20 | 23416728348467685 |
| 21 | 160500643816367088 |
| 22 | 1100087778366101931 |
| 23 | 7540113804746346429 |