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 | 3 |
| 2 | 11 |
| 3 | 43 |
| 4 | 174 |
| 5 | 721 |
| 6 | 3044 |
| 7 | 13059 |
| 8 | 56837 |
| 9 | 250690 |
| 10 | 1119612 |
| 11 | 5059561 |
| 12 | 23119628 |
| 13 | 106753404 |
| 14 | 497762380 |
| 15 | 2342096579 |
| 16 | 11113027686 |
| 17 | 53138757319 |
| 18 | 255892224332 |
| 19 | 1240217043450 |
| 20 | 6046131132030 |
| 21 | 29631889507380 |
| 22 | 145923474439800 |
| 23 | 721733515299225 |
| 24 | 3583733352377724 |