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 | 1 |
| 3 | 6 |
| 4 | 21 |
| 5 | 86 |
| 6 | 396 |
| 7 | 1812 |
| 8 | 8607 |
| 9 | 41958 |
| 10 | 207333 |
| 11 | 1040234 |
| 12 | 5281965 |
| 13 | 27078756 |
| 14 | 140021248 |
| 15 | 729369474 |
| 16 | 3823598232 |
| 17 | 20158251814 |
| 18 | 106809280563 |
| 19 | 568471343322 |
| 20 | 3037782047947 |
| 21 | 16292380484454 |
| 22 | 87669285293451 |
| 23 | 473172657154822 |