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 | 4 |
| 4 | 11 |
| 5 | 32 |
| 6 | 116 |
| 7 | 455 |
| 8 | 1993 |
| 9 | 9134 |
| 10 | 43580 |
| 11 | 211659 |
| 12 | 1041441 |
| 13 | 5156642 |
| 14 | 25640456 |
| 15 | 127773475 |
| 16 | 637624313 |
| 17 | 3184387574 |
| 18 | 15910947980 |
| 19 | 79521737939 |
| 20 | 397510726681 |
| 21 | 1987259550002 |
| 22 | 9935420646296 |
| 23 | 49674470817195 |
| 24 | 248364482308833 |
| 25 | 1241798790172214 |