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 | 3 |
| 3 | 9 |
| 4 | 36 |
| 5 | 156 |
| 6 | 754 |
| 7 | 3886 |
| 8 | 21239 |
| 9 | 121411 |
| 10 | 721189 |
| 11 | 4423167 |
| 12 | 27884979 |
| 13 | 180023715 |
| 14 | 1186646085 |
| 15 | 7966608939 |
| 16 | 54362492505 |
| 17 | 376401432105 |
| 18 | 2640553802523 |
| 19 | 18745081044417 |
| 20 | 134511480800046 |
| 21 | 974773373273658 |
| 22 | 7127937477283896 |
| 23 | 52556513927004360 |
| 24 | 390494071802647015 |