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) |
|---|---|
| 1 | 1 |
| 2 | 3 |
| 3 | 9 |
| 4 | 26 |
| 5 | 75 |
| 6 | 207 |
| 7 | 565 |
| 8 | 1518 |
| 9 | 4044 |
| 10 | 10703 |
| 11 | 28234 |
| 12 | 74277 |
| 13 | 195103 |
| 14 | 511902 |
| 15 | 1342147 |
| 16 | 3517239 |
| 17 | 9214412 |
| 18 | 24134528 |
| 19 | 63204417 |
| 20 | 165505811 |
| 21 | 433361425 |
| 22 | 1134664831 |
| 23 | 2970787794 |
| 24 | 7777975396 |
| 25 | 20363634815 |
| 26 | 53313819160 |
| 27 | 139579420528 |
| 28 | 365427311171 |
| 29 | 956707667616 |
| 30 | 2504704955181 |