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 | 0 |
| 1 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 5 |
| 5 | 11 |
| 6 | 30 |
| 7 | 80 |
| 8 | 228 |
| 9 | 656 |
| 10 | 1945 |
| 11 | 5835 |
| 12 | 17808 |
| 13 | 54881 |
| 14 | 170951 |
| 15 | 536726 |
| 16 | 1697774 |
| 17 | 5403629 |
| 18 | 17295686 |
| 19 | 55630538 |
| 20 | 179726346 |
| 21 | 582942079 |
| 22 | 1897565974 |
| 23 | 6196973039 |
| 24 | 20297954197 |
| 25 | 66666192488 |
| 26 | 219505550167 |
| 27 | 724415274090 |
| 28 | 2395838962114 |
| 29 | 7939424272536 |