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 | 8 |
| 2 | 34 |
| 3 | 122 |
| 4 | 502 |
| 5 | 2098 |
| 6 | 8980 |
| 7 | 38928 |
| 8 | 170382 |
| 9 | 750722 |
| 10 | 3323554 |
| 11 | 14763438 |
| 12 | 65736004 |
| 13 | 293186252 |
| 14 | 1309156946 |
| 15 | 5850527002 |
| 16 | 26160514526 |
| 17 | 117022825786 |
| 18 | 523619082772 |
| 19 | 2343388805944 |
| 20 | 10488943094022 |
| 21 | 46952619517170 |