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 | 1 |
| 1 | 6 |
| 2 | 31 |
| 3 | 133 |
| 4 | 587 |
| 5 | 2531 |
| 6 | 10950 |
| 7 | 47185 |
| 8 | 203704 |
| 9 | 879711 |
| 10 | 3804530 |
| 11 | 16464710 |
| 12 | 71312805 |
| 13 | 309083291 |
| 14 | 1340546867 |
| 15 | 5817555402 |
| 16 | 25258769216 |
| 17 | 109711224970 |
| 18 | 476675868834 |
| 19 | 2071569641859 |
| 20 | 9004430215111 |
| 21 | 39144480326143 |
| 22 | 170184867215647 |
| 23 | 739924236443359 |
| 24 | 3217001700174226 |