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 | 7 |
| 4 | 26 |
| 5 | 111 |
| 6 | 562 |
| 7 | 3151 |
| 8 | 19252 |
| 9 | 128449 |
| 10 | 925226 |
| 11 | 7125009 |
| 12 | 58399156 |
| 13 | 507222535 |
| 14 | 4647051970 |
| 15 | 44747776651 |
| 16 | 451520086208 |
| 17 | 4761032807937 |
| 18 | 52332895618066 |
| 19 | 598351410294193 |
| 20 | 7102331902602676 |
| 21 | 87365859333294151 |
| 22 | 1111941946738682522 |
| 23 | 14621347433458883187 |