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) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 3 |
| 5 | 3 |
| 6 | 17 |
| 7 | 94 |
| 8 | 158 |
| 9 | 213 |
| 10 | 571 |
| 11 | 1987 |
| 12 | 3163 |
| 13 | 27993 |
| 14 | 45176 |
| 15 | 205432 |
| 16 | 707079 |
| 17 | 2319521 |
| 18 | 7603409 |
| 19 | 25967812 |
| 20 | 83981455 |
| 21 | 310267532 |