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 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 1 |
| 5 | 4 |
| 6 | 10 |
| 7 | 20 |
| 8 | 125 |
| 9 | 461 |
| 10 | 1301 |
| 11 | 11210 |
| 12 | 55220 |
| 13 | 202840 |
| 14 | 2223859 |
| 15 | 13690951 |
| 16 | 61889101 |
| 17 | 823947856 |
| 18 | 6087160726 |
| 19 | 32676403052 |
| 20 | 511799407517 |
| 21 | 4411241879141 |
| 22 | 27418828825961 |
| 23 | 493869702112622 |
| 24 | 4864805677935368 |
| 25 | 34361404413755056 |
| 26 | 699648473127100771 |