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 | 7 |
| 2 | 27 |
| 3 | 84 |
| 4 | 270 |
| 5 | 826 |
| 6 | 2488 |
| 7 | 7353 |
| 8 | 21461 |
| 9 | 61960 |
| 10 | 177344 |
| 11 | 503892 |
| 12 | 1422892 |
| 13 | 3996619 |
| 14 | 11173935 |
| 15 | 31114236 |
| 16 | 86328978 |
| 17 | 238764238 |
| 18 | 658478176 |
| 19 | 1811322045 |
| 20 | 4970928809 |
| 21 | 13613135152 |
| 22 | 37208048132 |
| 23 | 101518052904 |
| 24 | 276527670100 |
| 25 | 752102592271 |