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 | 1 |
| 2 | 4 |
| 3 | 16 |
| 4 | 37 |
| 5 | 121 |
| 6 | 376 |
| 7 | 1072 |
| 8 | 3289 |
| 9 | 9889 |
| 10 | 29404 |
| 11 | 88672 |
| 12 | 265885 |
| 13 | 796537 |
| 14 | 2392240 |
| 15 | 7174816 |
| 16 | 21520369 |
| 17 | 64574977 |
| 18 | 193709428 |
| 19 | 581117680 |
| 20 | 1743420757 |
| 21 | 5230158649 |
| 22 | 15690480040 |
| 23 | 47071742800 |
| 24 | 141214610761 |
| 25 | 423644159521 |
| 26 | 1270933677004 |