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 | 5 |
| 2 | 25 |
| 3 | 55 |
| 4 | 275 |
| 5 | 935 |
| 6 | 3025 |
| 7 | 4675 |
| 8 | 21505 |
| 9 | 51425 |
| 10 | 107525 |
| 11 | 537625 |
| 12 | 1182775 |
| 13 | 2688125 |
| 14 | 3118225 |
| 15 | 15591125 |
| 16 | 34300475 |
| 17 | 77955625 |
| 18 | 127847225 |
| 19 | 583108075 |
| 20 | 639236125 |
| 21 | 1406319475 |
| 22 | 3196180625 |
| 23 | 6008819575 |
| 24 | 23907431075 |
| 25 | 30044097875 |
| 26 | 66097015325 |
| 27 | 150220489375 |
| 28 | 318467437475 |
| 29 | 1123649260525 |