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) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 7 |
| 5 | 23 |
| 6 | 115 |
| 7 | 694 |
| 8 | 5282 |
| 9 | 46066 |
| 10 | 456454 |
| 11 | 4999004 |
| 12 | 59916028 |
| 13 | 778525516 |
| 14 | 10897964660 |
| 15 | 163461964024 |
| 16 | 2615361578344 |
| 17 | 44460982752488 |
| 18 | 800296985768776 |
| 19 | 15205638776753680 |
| 20 | 304112757426239984 |
| 21 | 6386367801916347184 |