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 | 1 |
| 3 | 2 |
| 4 | 5 |
| 5 | 12 |
| 6 | 31 |
| 7 | 84 |
| 8 | 250 |
| 9 | 762 |
| 10 | 2504 |
| 11 | 8358 |
| 12 | 28928 |
| 13 | 101339 |
| 14 | 361184 |
| 15 | 1297864 |
| 16 | 4707712 |
| 17 | 17179434 |
| 18 | 63068079 |
| 19 | 232615770 |
| 20 | 861723271 |
| 21 | 3204236692 |
| 22 | 11955827898 |
| 23 | 44748176652 |
| 24 | 167959114814 |
| 25 | 632058070297 |
| 26 | 2384234976235 |
| 27 | 9013628450510 |