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) |
|---|---|
| 2 | 1 |
| 3 | 9 |
| 4 | 59 |
| 5 | 338 |
| 6 | 1937 |
| 7 | 10289 |
| 8 | 57345 |
| 9 | 299832 |
| 10 | 1663421 |
| 11 | 8705069 |
| 12 | 48391863 |
| 13 | 254818488 |
| 14 | 1421911953 |
| 15 | 7544528179 |
| 16 | 42264280735 |
| 17 | 225949128338 |
| 18 | 1270219491983 |
| 19 | 6838142459779 |
| 20 | 38557301241769 |
| 21 | 208865221891584 |
| 22 | 1180647902778713 |
| 23 | 6430734346787925 |
| 24 | 36426544777112515 |
| 25 | 199364753897943071 |