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 | 5 |
| 3 | 35 |
| 4 | 165 |
| 5 | 1177 |
| 6 | 9407 |
| 7 | 55657 |
| 8 | 372429 |
| 9 | 2766100 |
| 10 | 17671945 |
| 11 | 118674685 |
| 12 | 837152398 |
| 13 | 5531816082 |
| 14 | 37328192350 |
| 15 | 257252634864 |
| 16 | 1725117502706 |
| 17 | 11666552132346 |
| 18 | 79612474584518 |
| 19 | 537157628862720 |
| 20 | 3636277021289585 |
| 21 | 24711657036469040 |
| 22 | 167150255133278869 |