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 | 11 |
| 3 | 43 |
| 4 | 280 |
| 5 | 1563 |
| 6 | 9415 |
| 7 | 55553 |
| 8 | 331133 |
| 9 | 1968400 |
| 10 | 11716601 |
| 11 | 69716257 |
| 12 | 414898579 |
| 13 | 2469046811 |
| 14 | 14693544104 |
| 15 | 87442204835 |
| 16 | 520375602855 |
| 17 | 3096794588441 |
| 18 | 18429266069421 |
| 19 | 109673987617376 |
| 20 | 652678415082545 |
| 21 | 3884139865306433 |
| 22 | 23114817718082715 |
| 23 | 137558073518189643 |