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 | 4 |
| 1 | 12 |
| 2 | 38 |
| 3 | 118 |
| 4 | 362 |
| 5 | 1082 |
| 6 | 3166 |
| 7 | 8910 |
| 8 | 24426 |
| 9 | 64226 |
| 10 | 165262 |
| 11 | 413418 |
| 12 | 1021362 |
| 13 | 2490686 |
| 14 | 6009150 |
| 15 | 14401410 |
| 16 | 34098042 |
| 17 | 80281962 |
| 18 | 187356750 |
| 19 | 432549154 |
| 20 | 992941250 |
| 21 | 2256712462 |
| 22 | 5088826238 |
| 23 | 11408805862 |
| 24 | 25425739346 |
| 25 | 56383362854 |
| 26 | 124565557898 |
| 27 | 274390550594 |