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 | 7 |
| 3 | 12 |
| 4 | 23 |
| 5 | 44 |
| 6 | 97 |
| 7 | 212 |
| 8 | 512 |
| 9 | 1260 |
| 10 | 3251 |
| 11 | 8540 |
| 12 | 23035 |
| 13 | 62780 |
| 14 | 173453 |
| 15 | 482692 |
| 16 | 1353077 |
| 17 | 3811364 |
| 18 | 10785235 |
| 19 | 30625196 |
| 20 | 87239999 |
| 21 | 249174236 |
| 22 | 713416601 |
| 23 | 2046945140 |
| 24 | 5884580074 |
| 25 | 16946835092 |
| 26 | 48883925867 |
| 27 | 141217957620 |
| 28 | 408519816611 |
| 29 | 1183291934300 |
| 30 | 3431535849813 |