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 | 5 |
| 2 | 18 |
| 3 | 65 |
| 4 | 238 |
| 5 | 882 |
| 6 | 3300 |
| 7 | 12441 |
| 8 | 47190 |
| 9 | 179894 |
| 10 | 688636 |
| 11 | 2645370 |
| 12 | 10192588 |
| 13 | 39373700 |
| 14 | 152443080 |
| 15 | 591385545 |
| 16 | 2298248550 |
| 17 | 8945490510 |
| 18 | 34867625100 |
| 19 | 136079265630 |
| 20 | 531693754020 |
| 21 | 2079632696700 |
| 22 | 8141948163960 |
| 23 | 31904544069450 |
| 24 | 125120702290428 |
| 25 | 491056586546652 |