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 | 38 |
| 4 | 257 |
| 5 | 1935 |
| 6 | 15505 |
| 7 | 129519 |
| 8 | 1115061 |
| 9 | 9823160 |
| 10 | 88121887 |
| 11 | 802227794 |
| 12 | 7392428009 |
| 13 | 68819554003 |
| 14 | 646276497617 |
| 15 | 6114880542117 |
| 16 | 58237420303109 |
| 17 | 557850829527246 |
| 18 | 5370956411708779 |
| 19 | 51947475492561014 |
| 20 | 504492516832543885 |
| 21 | 4917564488572565160 |