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 | 6 |
| 3 | 25 |
| 4 | 103 |
| 5 | 399 |
| 6 | 1532 |
| 7 | 5754 |
| 8 | 21383 |
| 9 | 78735 |
| 10 | 288580 |
| 11 | 1053894 |
| 12 | 3840866 |
| 13 | 13981403 |
| 14 | 50874249 |
| 15 | 185128907 |
| 16 | 673970102 |
| 17 | 2455319377 |
| 18 | 8952722626 |
| 19 | 32676307483 |
| 20 | 119391572211 |
| 21 | 436711281979 |
| 22 | 1599194641093 |
| 23 | 5862625449021 |
| 24 | 21515851244159 |