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) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 3 |
| 4 | 11 |
| 5 | 35 |
| 6 | 114 |
| 7 | 407 |
| 8 | 1486 |
| 9 | 5414 |
| 10 | 19923 |
| 11 | 74230 |
| 12 | 278462 |
| 13 | 1049318 |
| 14 | 3972395 |
| 15 | 15101658 |
| 16 | 57607431 |
| 17 | 220391316 |
| 18 | 845366406 |
| 19 | 3250192681 |
| 20 | 12521965697 |