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 | 6 |
| 2 | 21 |
| 3 | 61 |
| 4 | 161 |
| 5 | 401 |
| 6 | 961 |
| 7 | 2241 |
| 8 | 5121 |
| 9 | 11521 |
| 10 | 25601 |
| 11 | 56321 |
| 12 | 122881 |
| 13 | 266241 |
| 14 | 573441 |
| 15 | 1228801 |
| 16 | 2621441 |
| 17 | 5570561 |
| 18 | 11796481 |
| 19 | 24903681 |
| 20 | 52428801 |
| 21 | 110100481 |
| 22 | 230686721 |
| 23 | 482344961 |
| 24 | 1006632961 |
| 25 | 2097152001 |
| 26 | 4362076161 |
| 27 | 9059696641 |
| 28 | 18790481921 |
| 29 | 38923141121 |