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 | 2 |
| 3 | 4 |
| 4 | 11 |
| 5 | 41 |
| 6 | 189 |
| 7 | 1020 |
| 8 | 6277 |
| 9 | 43262 |
| 10 | 328963 |
| 11 | 2727076 |
| 12 | 24425913 |
| 13 | 234743744 |
| 14 | 2406904525 |
| 15 | 26202132494 |
| 16 | 301579542517 |
| 17 | 3656552470482 |
| 18 | 46555182556971 |
| 19 | 620695577790512 |
| 20 | 8644238847922949 |
| 21 | 125472134647552497 |
| 22 | 1894393648378487895 |
| 23 | 29696659293381522674 |