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 | 3 |
| 2 | 10 |
| 3 | 31 |
| 4 | 95 |
| 5 | 288 |
| 6 | 869 |
| 7 | 2615 |
| 8 | 7858 |
| 9 | 23595 |
| 10 | 70819 |
| 11 | 212512 |
| 12 | 637625 |
| 13 | 1913019 |
| 14 | 5739290 |
| 15 | 17218247 |
| 16 | 51655351 |
| 17 | 154967040 |
| 18 | 464902717 |
| 19 | 1394710735 |
| 20 | 4184136386 |
| 21 | 12552415923 |
| 22 | 37657258715 |
| 23 | 112971793856 |
| 24 | 338915410225 |
| 25 | 1016746277043 |