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 | 19 |
| 3 | 67 |
| 4 | 232 |
| 5 | 804 |
| 6 | 2806 |
| 7 | 9878 |
| 8 | 35072 |
| 9 | 125512 |
| 10 | 452388 |
| 11 | 1641028 |
| 12 | 5986993 |
| 13 | 21954973 |
| 14 | 80884423 |
| 15 | 299233543 |
| 16 | 1111219333 |
| 17 | 4140813373 |
| 18 | 15478839553 |
| 19 | 58028869153 |
| 20 | 218123355523 |
| 21 | 821908275547 |
| 22 | 3104046382351 |
| 23 | 11747506651599 |