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 | 0 |
| 1 | 1 |
| 2 | 3 |
| 3 | 11 |
| 4 | 42 |
| 5 | 164 |
| 6 | 649 |
| 7 | 2591 |
| 8 | 10408 |
| 9 | 41998 |
| 10 | 170050 |
| 11 | 690370 |
| 12 | 2808714 |
| 13 | 11446642 |
| 14 | 46715469 |
| 15 | 190876527 |
| 16 | 780679200 |
| 17 | 3195628806 |
| 18 | 13090353594 |
| 19 | 53655587034 |
| 20 | 220045073988 |
| 21 | 902842397664 |
| 22 | 3705876933930 |
| 23 | 15216954519222 |
| 24 | 62503485455208 |