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 | 7 |
| 2 | 42 |
| 3 | 203 |
| 4 | 882 |
| 5 | 3486 |
| 6 | 12880 |
| 7 | 44885 |
| 8 | 149170 |
| 9 | 475587 |
| 10 | 1462993 |
| 11 | 4359474 |
| 12 | 12628091 |
| 13 | 35656446 |
| 14 | 98372109 |
| 15 | 265701212 |
| 16 | 703800790 |
| 17 | 1830960824 |
| 18 | 4684293222 |
| 19 | 11798774953 |
| 20 | 29288385021 |
| 21 | 71714795158 |
| 22 | 173351031721 |
| 23 | 413964243476 |
| 24 | 977243358574 |
| 25 | 2281942600035 |
| 26 | 5273570826594 |