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 | 10 |
| 2 | 64 |
| 3 | 331 |
| 4 | 1505 |
| 5 | 6272 |
| 6 | 24540 |
| 7 | 91527 |
| 8 | 328768 |
| 9 | 1145650 |
| 10 | 3893630 |
| 11 | 12958400 |
| 12 | 42364427 |
| 13 | 136389128 |
| 14 | 433263360 |
| 15 | 1360269093 |
| 16 | 4226523495 |
| 17 | 13011186624 |
| 18 | 39722775806 |
| 19 | 120366164765 |
| 20 | 362255552384 |
| 21 | 1083513943700 |