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 | 10 |
| 2 | 73 |
| 3 | 486 |
| 4 | 2907 |
| 5 | 15930 |
| 6 | 81586 |
| 7 | 394251 |
| 8 | 1807754 |
| 9 | 7903501 |
| 10 | 33107532 |
| 11 | 133503791 |
| 12 | 520255432 |
| 13 | 1965535471 |
| 14 | 7218099342 |
| 15 | 25820149509 |
| 16 | 90120974981 |
| 17 | 307356231936 |
| 18 | 1025551245320 |
| 19 | 3351842646799 |
| 20 | 10742435671415 |