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 | 9 |
| 3 | 28 |
| 4 | 104 |
| 5 | 367 |
| 6 | 1295 |
| 7 | 4600 |
| 8 | 17229 |
| 9 | 64069 |
| 10 | 238148 |
| 11 | 886823 |
| 12 | 3366045 |
| 13 | 12793452 |
| 14 | 48663267 |
| 15 | 185303586 |
| 16 | 711046282 |
| 17 | 2734845898 |
| 18 | 10532016662 |
| 19 | 40599379289 |
| 20 | 157049408777 |
| 21 | 608667818351 |
| 22 | 2361851906708 |
| 23 | 9173261457282 |