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 | 5 |
| 2 | 17 |
| 3 | 65 |
| 4 | 229 |
| 5 | 813 |
| 6 | 2945 |
| 7 | 10513 |
| 8 | 37701 |
| 9 | 135261 |
| 10 | 484609 |
| 11 | 1737665 |
| 12 | 6229413 |
| 13 | 22330829 |
| 14 | 80057281 |
| 15 | 286996657 |
| 16 | 1028861637 |
| 17 | 3688409853 |
| 18 | 13222664897 |
| 19 | 47402353633 |
| 20 | 169934149285 |
| 21 | 609201913325 |
| 22 | 2183946525185 |
| 23 | 7829295473489 |
| 24 | 28067476697413 |
| 25 | 100619943566493 |