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 | 1 |
| 2 | 5 |
| 3 | 19 |
| 4 | 85 |
| 5 | 402 |
| 6 | 1971 |
| 7 | 9976 |
| 8 | 51633 |
| 9 | 272131 |
| 10 | 1455486 |
| 11 | 7879664 |
| 12 | 43096967 |
| 13 | 237777710 |
| 14 | 1321792096 |
| 15 | 7396125088 |
| 16 | 41624735353 |
| 17 | 235461758085 |
| 18 | 1338049873395 |
| 19 | 7634930866465 |
| 20 | 43726638130854 |
| 21 | 251273386911443 |
| 22 | 1448362622788376 |
| 23 | 8371936106228253 |