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 | 5 |
| 2 | 15 |
| 3 | 55 |
| 4 | 205 |
| 5 | 829 |
| 6 | 3409 |
| 7 | 14569 |
| 8 | 63319 |
| 9 | 280319 |
| 10 | 1256567 |
| 11 | 5695487 |
| 12 | 26039187 |
| 13 | 119939427 |
| 14 | 555899247 |
| 15 | 2590404239 |
| 16 | 12127122989 |
| 17 | 57005914349 |
| 18 | 268933430849 |
| 19 | 1272801132329 |
| 20 | 6041172226049 |
| 21 | 28747703565329 |
| 22 | 137119782755669 |
| 23 | 655421041672109 |
| 24 | 3138947897124609 |