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 | 3 |
| 3 | 10 |
| 4 | 35 |
| 5 | 126 |
| 6 | 462 |
| 7 | 1716 |
| 8 | 6435 |
| 9 | 24301 |
| 10 | 92278 |
| 11 | 351990 |
| 12 | 1347710 |
| 13 | 5176640 |
| 14 | 19938348 |
| 15 | 76977360 |
| 16 | 297811491 |
| 17 | 1154300103 |
| 18 | 4481325903 |
| 19 | 17423296059 |
| 20 | 67830758310 |
| 21 | 264387659490 |
| 22 | 1031636761290 |
| 23 | 4029420952890 |
| 24 | 15752622069630 |
| 25 | 61634789550126 |
| 26 | 241342568718696 |