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 | 5 |
| 4 | 15 |
| 5 | 53 |
| 6 | 216 |
| 7 | 994 |
| 8 | 5076 |
| 9 | 28403 |
| 10 | 172538 |
| 11 | 1129511 |
| 12 | 7919314 |
| 13 | 59150556 |
| 14 | 468504022 |
| 15 | 3919569708 |
| 16 | 34518111783 |
| 17 | 319030219223 |
| 18 | 3086250047021 |
| 19 | 31174921402976 |
| 20 | 328110078110137 |
| 21 | 3591110146030066 |
| 22 | 40800503952916639 |
| 23 | 480429785491094856 |
| 24 | 5854374278697301978 |