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 | 2 |
| 3 | 9 |
| 4 | 44 |
| 5 | 226 |
| 6 | 1241 |
| 7 | 7093 |
| 8 | 41666 |
| 9 | 250260 |
| 10 | 1529993 |
| 11 | 9488398 |
| 12 | 59545909 |
| 13 | 377451385 |
| 14 | 2413157855 |
| 15 | 15542535697 |
| 16 | 100753850132 |
| 17 | 656856027658 |
| 18 | 4303970039402 |
| 19 | 28328599504756 |
| 20 | 187214549485759 |
| 21 | 1241775795647609 |
| 22 | 8263989319451514 |
| 23 | 55163575187733922 |