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 | 10 |
| 2 | 44 |
| 3 | 200 |
| 4 | 918 |
| 5 | 4236 |
| 6 | 19598 |
| 7 | 90790 |
| 8 | 420870 |
| 9 | 1951636 |
| 10 | 9051480 |
| 11 | 41983154 |
| 12 | 194736668 |
| 13 | 903293618 |
| 14 | 4190003458 |
| 15 | 19435777562 |
| 16 | 90155141564 |
| 17 | 418195731384 |
| 18 | 1939853565942 |
| 19 | 8998257693932 |
| 20 | 41739569773726 |
| 21 | 193614349514214 |