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 | 7 |
| 3 | 50 |
| 4 | 311 |
| 5 | 1954 |
| 6 | 11914 |
| 7 | 76003 |
| 8 | 467221 |
| 9 | 2943211 |
| 10 | 18261840 |
| 11 | 114360149 |
| 12 | 712196192 |
| 13 | 4449548684 |
| 14 | 27749537725 |
| 15 | 173227638835 |
| 16 | 1080825788517 |
| 17 | 6745415139188 |
| 18 | 42092502492537 |
| 19 | 262680587755837 |
| 20 | 1639226363457986 |
| 21 | 10229514197548963 |
| 22 | 63836523795617745 |