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) |
|---|---|
| 1 | 4 |
| 2 | 8 |
| 3 | 28 |
| 4 | 48 |
| 5 | 148 |
| 6 | 248 |
| 7 | 748 |
| 8 | 1248 |
| 9 | 3748 |
| 10 | 6248 |
| 11 | 18748 |
| 12 | 31248 |
| 13 | 93748 |
| 14 | 156248 |
| 15 | 468748 |
| 16 | 781248 |
| 17 | 2343748 |
| 18 | 3906248 |
| 19 | 11718748 |
| 20 | 19531248 |
| 21 | 58593748 |
| 22 | 97656248 |
| 23 | 292968748 |
| 24 | 488281248 |
| 25 | 1464843748 |
| 26 | 2441406248 |
| 27 | 7324218748 |
| 28 | 12207031248 |
| 29 | 36621093748 |
| 30 | 61035156248 |