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 | 0 |
| 1 | 1 |
| 2 | 4 |
| 3 | 13 |
| 4 | 39 |
| 5 | 110 |
| 6 | 300 |
| 7 | 801 |
| 8 | 2106 |
| 9 | 5473 |
| 10 | 14097 |
| 11 | 36056 |
| 12 | 91697 |
| 13 | 232108 |
| 14 | 585212 |
| 15 | 1470557 |
| 16 | 3684682 |
| 17 | 9209417 |
| 18 | 22967446 |
| 19 | 57167993 |
| 20 | 142051519 |
| 21 | 352427720 |
| 22 | 873157093 |
| 23 | 2160579740 |
| 24 | 5340150100 |
| 25 | 13185150903 |
| 26 | 32523933395 |
| 27 | 80156852042 |
| 28 | 197391001215 |
| 29 | 485723767342 |