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 | 12 |
| 3 | 65 |
| 4 | 465 |
| 5 | 4212 |
| 6 | 46441 |
| 7 | 604389 |
| 8 | 9071250 |
| 9 | 154267865 |
| 10 | 2931801639 |
| 11 | 61578273462 |
| 12 | 1416474723373 |
| 13 | 35415138314415 |
| 14 | 956276678789100 |
| 15 | 27733572777976973 |
| 16 | 859779201497486829 |
| 17 | 28373745267763162716 |
| 18 | 993110842735800666085 |
| 19 | 36746019445535955976665 |