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 | 4 |
| 2 | 10 |
| 3 | 26 |
| 4 | 66 |
| 5 | 166 |
| 6 | 414 |
| 7 | 1026 |
| 8 | 2530 |
| 9 | 6214 |
| 10 | 15214 |
| 11 | 37154 |
| 12 | 90546 |
| 13 | 220294 |
| 14 | 535230 |
| 15 | 1298946 |
| 16 | 3149506 |
| 17 | 7630726 |
| 18 | 18476494 |
| 19 | 44714786 |
| 20 | 108168210 |
| 21 | 261575494 |
| 22 | 632367774 |
| 23 | 1528408194 |
| 24 | 3693378466 |
| 25 | 8923553734 |
| 26 | 21557263150 |
| 27 | 52071634466 |