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 | 7 |
| 4 | 17 |
| 5 | 51 |
| 6 | 205 |
| 7 | 1079 |
| 8 | 6993 |
| 9 | 53227 |
| 10 | 462341 |
| 11 | 4500255 |
| 12 | 48454969 |
| 13 | 571411283 |
| 14 | 7321388397 |
| 15 | 101249656711 |
| 16 | 1502852293025 |
| 17 | 23827244817339 |
| 18 | 401839065437653 |
| 19 | 7182224591785967 |
| 20 | 135607710526966281 |
| 21 | 2696935204638786595 |
| 22 | 56349204870460046909 |
| 23 | 1234002202313888987223 |