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 | 4 |
| 2 | 9 |
| 3 | 40 |
| 4 | 89 |
| 5 | 396 |
| 6 | 881 |
| 7 | 3920 |
| 8 | 8721 |
| 9 | 38804 |
| 10 | 86329 |
| 11 | 384120 |
| 12 | 854569 |
| 13 | 3802396 |
| 14 | 8459361 |
| 15 | 37639840 |
| 16 | 83739041 |
| 17 | 372596004 |
| 18 | 828931049 |
| 19 | 3688320200 |
| 20 | 8205571449 |
| 21 | 36510605996 |
| 22 | 81226783441 |
| 23 | 361417739760 |
| 24 | 804062262961 |
| 25 | 3577666791604 |
| 26 | 7959395846169 |
| 27 | 35415250176280 |