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 | 2 |
| 2 | 7 |
| 3 | 27 |
| 4 | 109 |
| 5 | 459 |
| 6 | 2006 |
| 7 | 9017 |
| 8 | 41384 |
| 9 | 193048 |
| 10 | 912571 |
| 11 | 4361939 |
| 12 | 21045710 |
| 13 | 102361864 |
| 14 | 501349447 |
| 15 | 2470556294 |
| 16 | 12240270901 |
| 17 | 60935582862 |
| 18 | 304660949343 |
| 19 | 1529125824203 |
| 20 | 7701783889261 |
| 21 | 38915600049447 |
| 22 | 197206343307012 |
| 23 | 1002023916642621 |
| 24 | 5103911800972155 |
| 25 | 26056404563941575 |