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 | 2 |
| 2 | 7 |
| 3 | 30 |
| 4 | 142 |
| 5 | 716 |
| 6 | 3771 |
| 7 | 20502 |
| 8 | 114194 |
| 9 | 648276 |
| 10 | 3737270 |
| 11 | 21819980 |
| 12 | 128757020 |
| 13 | 766680856 |
| 14 | 4600866643 |
| 15 | 27797553638 |
| 16 | 168949310378 |
| 17 | 1032267189636 |
| 18 | 6336728149794 |
| 19 | 39062959379620 |
| 20 | 241720286906116 |
| 21 | 1500910751651752 |
| 22 | 9348824475860702 |
| 23 | 58398701313158780 |