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 | 2 |
| 3 | 5 |
| 4 | 19 |
| 5 | 83 |
| 6 | 501 |
| 7 | 3217 |
| 8 | 26489 |
| 9 | 223001 |
| 10 | 2307265 |
| 11 | 23964881 |
| 12 | 297799569 |
| 13 | 3677298385 |
| 14 | 53294334289 |
| 15 | 762583317329 |
| 16 | 12621599431489 |
| 17 | 205355314491969 |
| 18 | 3820420692695361 |
| 19 | 69655479737261377 |
| 20 | 1438574866261997777 |
| 21 | 29053167748430247953 |
| 22 | 659456581268987396785 |
| 23 | 14613762897810470264817 |