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 | 0 |
| 2 | 1 |
| 3 | 2 |
| 4 | 4 |
| 5 | 9 |
| 6 | 26 |
| 7 | 68 |
| 8 | 217 |
| 9 | 718 |
| 10 | 2553 |
| 11 | 9574 |
| 12 | 38005 |
| 13 | 157306 |
| 14 | 679682 |
| 15 | 3047699 |
| 16 | 14150278 |
| 17 | 67844305 |
| 18 | 335262807 |
| 19 | 1704500229 |
| 20 | 8902528600 |
| 21 | 47704608478 |
| 22 | 261960998230 |
| 23 | 1472618327415 |
| 24 | 8466681788462 |
| 25 | 49743177379613 |
| 26 | 298407523833717 |
| 27 | 1826531247381194 |
| 28 | 11399711132242500 |
| 29 | 72500116125222893 |
| 30 | 469578870456459042 |