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 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 5 |
| 5 | 13 |
| 6 | 46 |
| 7 | 172 |
| 8 | 777 |
| 9 | 3783 |
| 10 | 20074 |
| 11 | 111604 |
| 12 | 646409 |
| 13 | 3846640 |
| 14 | 23410035 |
| 15 | 144965988 |
| 16 | 910898943 |
| 17 | 5794179218 |
| 18 | 37248630398 |
| 19 | 241676806702 |
| 20 | 1580880366039 |
| 21 | 10416314047854 |
| 22 | 69080674190341 |
| 23 | 460841447382976 |
| 24 | 3090747326749823 |