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 | 3 |
| 2 | 22 |
| 3 | 176 |
| 4 | 1471 |
| 5 | 12616 |
| 6 | 110056 |
| 7 | 971712 |
| 8 | 8656937 |
| 9 | 77663192 |
| 10 | 700614760 |
| 11 | 6349125440 |
| 12 | 57754842117 |
| 13 | 527046644056 |
| 14 | 4822774262296 |
| 15 | 44235726874816 |
| 16 | 406582639811581 |
| 17 | 3743845040832376 |
| 18 | 34529632747211560 |
| 19 | 318931047174438720 |
| 20 | 2949641596923575548 |
| 21 | 27312107861301870368 |