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 | 5 |
| 2 | 17 |
| 3 | 59 |
| 4 | 205 |
| 5 | 713 |
| 6 | 2481 |
| 7 | 8635 |
| 8 | 30057 |
| 9 | 104629 |
| 10 | 364225 |
| 11 | 1267923 |
| 12 | 4413861 |
| 13 | 15365465 |
| 14 | 53490097 |
| 15 | 186209299 |
| 16 | 648230545 |
| 17 | 2256616133 |
| 18 | 7855718641 |
| 19 | 27347281995 |
| 20 | 95201200637 |
| 21 | 331413874569 |
| 22 | 1153716087665 |
| 23 | 4016309864843 |
| 24 | 13981555011321 |
| 25 | 48672509644725 |