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 | 5 |
| 3 | 18 |
| 4 | 68 |
| 5 | 233 |
| 6 | 838 |
| 7 | 2989 |
| 8 | 10687 |
| 9 | 38097 |
| 10 | 136002 |
| 11 | 485370 |
| 12 | 1732377 |
| 13 | 6182628 |
| 14 | 22065919 |
| 15 | 78752901 |
| 16 | 281068809 |
| 17 | 1003130814 |
| 18 | 3580164896 |
| 19 | 12777572157 |
| 20 | 45603031014 |
| 21 | 162756761629 |
| 22 | 580877276331 |
| 23 | 2073145244569 |
| 24 | 7399034871398 |
| 25 | 26407082201462 |
| 26 | 94246615039341 |