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 | 11 |
| 2 | 49 |
| 3 | 179 |
| 4 | 757 |
| 5 | 3241 |
| 6 | 14233 |
| 7 | 63333 |
| 8 | 284877 |
| 9 | 1291697 |
| 10 | 5894119 |
| 11 | 27031653 |
| 12 | 124481521 |
| 13 | 575160311 |
| 14 | 2664800299 |
| 15 | 12374329729 |
| 16 | 57568895517 |
| 17 | 268238883291 |
| 18 | 1251429223153 |
| 19 | 5844466935453 |
| 20 | 27318547433927 |
| 21 | 127784523940077 |