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 | 23 |
| 3 | 113 |
| 4 | 579 |
| 5 | 3047 |
| 6 | 16319 |
| 7 | 88489 |
| 8 | 484255 |
| 9 | 2668951 |
| 10 | 14793169 |
| 11 | 82372723 |
| 12 | 460436551 |
| 13 | 2582033519 |
| 14 | 14519686915 |
| 15 | 81845419777 |
| 16 | 462319557311 |
| 17 | 2616334071987 |
| 18 | 14830559353869 |
| 19 | 84189874112659 |
| 20 | 478559722392493 |