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 | 9 |
| 3 | 31 |
| 4 | 117 |
| 5 | 471 |
| 6 | 2053 |
| 7 | 9339 |
| 8 | 45321 |
| 9 | 227467 |
| 10 | 1203681 |
| 11 | 6556023 |
| 12 | 37316029 |
| 13 | 217944351 |
| 14 | 1321360797 |
| 15 | 8201728531 |
| 16 | 52577120913 |
| 17 | 344433580179 |
| 18 | 2321103364921 |
| 19 | 15960060854607 |
| 20 | 112534486969221 |
| 21 | 808555930139623 |
| 22 | 5942117054417589 |
| 23 | 44446333314841131 |