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 | 6 |
| 2 | 30 |
| 3 | 126 |
| 4 | 498 |
| 5 | 1982 |
| 6 | 7854 |
| 7 | 31014 |
| 8 | 122562 |
| 9 | 484422 |
| 10 | 1914254 |
| 11 | 7564542 |
| 12 | 29893554 |
| 13 | 118131966 |
| 14 | 466827678 |
| 15 | 1844789414 |
| 16 | 7290156162 |
| 17 | 28808903814 |
| 18 | 113845717662 |
| 19 | 449890341534 |
| 20 | 1777856189330 |
| 21 | 7025651266782 |
| 22 | 27763649373966 |
| 23 | 109715127592326 |
| 24 | 433567254075330 |
| 25 | 1713351367231142 |
| 26 | 6770744053574286 |