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 | 2 |
| 2 | 5 |
| 3 | 12 |
| 4 | 30 |
| 5 | 76 |
| 6 | 197 |
| 7 | 520 |
| 8 | 1398 |
| 9 | 3820 |
| 10 | 10594 |
| 11 | 29768 |
| 12 | 84620 |
| 13 | 243000 |
| 14 | 704045 |
| 15 | 2055760 |
| 16 | 6043750 |
| 17 | 17875020 |
| 18 | 53148310 |
| 19 | 158773320 |
| 20 | 476311940 |
| 21 | 1434313960 |
| 22 | 4333867170 |
| 23 | 13135533552 |
| 24 | 39924668220 |
| 25 | 121661345656 |
| 26 | 371612931492 |