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 | 4 |
| 1 | 1 |
| 2 | 13 |
| 3 | 13 |
| 4 | 73 |
| 5 | 121 |
| 6 | 481 |
| 7 | 1009 |
| 8 | 3361 |
| 9 | 7969 |
| 10 | 24193 |
| 11 | 61249 |
| 12 | 177025 |
| 13 | 464257 |
| 14 | 1307137 |
| 15 | 3493633 |
| 16 | 9699841 |
| 17 | 26190337 |
| 18 | 72173569 |
| 19 | 195941377 |
| 20 | 537802753 |
| 21 | 1464342529 |
| 22 | 4010582017 |
| 23 | 10937266177 |
| 24 | 29920862209 |
| 25 | 81665925121 |
| 26 | 223274237953 |
| 27 | 609678999553 |
| 28 | 1666309128193 |