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 | 0 |
| 2 | 1 |
| 3 | 9 |
| 4 | 74 |
| 5 | 594 |
| 6 | 4755 |
| 7 | 38043 |
| 8 | 304348 |
| 9 | 2434788 |
| 10 | 19478309 |
| 11 | 155826477 |
| 12 | 1246611822 |
| 13 | 9972894582 |
| 14 | 79783156663 |
| 15 | 638265253311 |
| 16 | 5106122026496 |
| 17 | 40848976211976 |
| 18 | 326791809695817 |
| 19 | 2614334477566545 |
| 20 | 20914675820532370 |
| 21 | 167317406564258970 |
| 22 | 1338539252514071771 |
| 23 | 10708314020112574179 |
| 24 | 85666512160900593444 |
| 25 | 685332097287204747564 |