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 | 1 |
| 3 | 2 |
| 4 | 5 |
| 5 | 7 |
| 6 | 10 |
| 7 | 34 |
| 8 | 278 |
| 9 | 751 |
| 10 | 2157 |
| 11 | 22208 |
| 12 | 676327 |
| 13 | 2225346 |
| 14 | 23259536 |
| 15 | 265050967 |
| 16 | 39161483067 |
| 17 | 70455119174849 |
| 18 | 776384598617893 |
| 19 | 133991542908557129 |
| 20 | 21819590324155207874 |
| 21 | 263763825614848727692 |
| 22 | 12883245190231409112736 |
| 23 | 661394651111310011564685 |