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 | 0 |
| 1 | 1 |
| 2 | 1 |
| 3 | 5 |
| 4 | 18 |
| 5 | 101 |
| 6 | 611 |
| 7 | 4452 |
| 8 | 36287 |
| 9 | 333395 |
| 10 | 3382758 |
| 11 | 37688597 |
| 12 | 456839351 |
| 13 | 5989023768 |
| 14 | 84421235807 |
| 15 | 1273482972215 |
| 16 | 20470309460322 |
| 17 | 349326503482301 |
| 18 | 6307682420743595 |
| 19 | 120157254334350828 |
| 20 | 2408293016265606623 |
| 21 | 50663563124372167787 |
| 22 | 1116225038923857181614 |