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 | 2 |
| 3 | 9 |
| 4 | 43 |
| 5 | 198 |
| 6 | 903 |
| 7 | 4121 |
| 8 | 18840 |
| 9 | 86255 |
| 10 | 395397 |
| 11 | 1814662 |
| 12 | 8337729 |
| 13 | 38350063 |
| 14 | 176574336 |
| 15 | 813785593 |
| 16 | 3753980313 |
| 17 | 17332179596 |
| 18 | 80089232683 |
| 19 | 370370470791 |
| 20 | 1714045215632 |
| 21 | 7938075605697 |
| 22 | 36787429315319 |
| 23 | 170592514889814 |
| 24 | 791557946825363 |
| 25 | 3674974608196665 |