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 | 5 |
| 2 | 20 |
| 3 | 87 |
| 4 | 409 |
| 5 | 2066 |
| 6 | 11155 |
| 7 | 64077 |
| 8 | 389946 |
| 9 | 2504665 |
| 10 | 16923381 |
| 11 | 119928232 |
| 12 | 888980293 |
| 13 | 6876320041 |
| 14 | 55382419676 |
| 15 | 463539664643 |
| 16 | 4024626253845 |
| 17 | 36189297168874 |
| 18 | 336513491259647 |
| 19 | 3231446022478129 |
| 20 | 32004743929977258 |
| 21 | 326548129128737469 |
| 22 | 3428663026172389201 |