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 | 20 |
| 2 | 209 |
| 3 | 1520 |
| 4 | 8644 |
| 5 | 40944 |
| 6 | 168035 |
| 7 | 613756 |
| 8 | 2034120 |
| 9 | 6206596 |
| 10 | 17632836 |
| 11 | 47062620 |
| 12 | 118870650 |
| 13 | 285840940 |
| 14 | 657667521 |
| 15 | 1454009144 |
| 16 | 3100176535 |
| 17 | 6394814820 |
| 18 | 12796122680 |
| 19 | 24898749084 |
| 20 | 47210910669 |
| 21 | 87394933080 |
| 22 | 158210114281 |
| 23 | 280501917580 |
| 24 | 487725327805 |
| 25 | 832684314712 |