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 | 6 |
| 4 | 21 |
| 5 | 78 |
| 6 | 299 |
| 7 | 1176 |
| 8 | 4729 |
| 9 | 19378 |
| 10 | 80667 |
| 11 | 340260 |
| 12 | 1451277 |
| 13 | 6248758 |
| 14 | 27124703 |
| 15 | 118576648 |
| 16 | 521574769 |
| 17 | 2306766426 |
| 18 | 10251761219 |
| 19 | 45759404076 |
| 20 | 205050758165 |
| 21 | 922104978430 |
| 22 | 4160045001703 |
| 23 | 18823187479504 |
| 24 | 85400356099001 |
| 25 | 388422301113250 |
| 26 | 1770695668597643 |
| 27 | 8089198184655732 |
| 28 | 37027394471695197 |