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 | 5 |
| 3 | 25 |
| 4 | 135 |
| 5 | 625 |
| 6 | 3250 |
| 7 | 15625 |
| 8 | 78760 |
| 9 | 390925 |
| 10 | 1956250 |
| 11 | 9765625 |
| 12 | 48847125 |
| 13 | 244140625 |
| 14 | 1220781250 |
| 15 | 6103531250 |
| 16 | 30517977755 |
| 17 | 152587890625 |
| 18 | 762941485875 |
| 19 | 3814697265625 |
| 20 | 19073496178125 |
| 21 | 95367432031250 |
| 22 | 476837207031250 |
| 23 | 2384185791015625 |
| 24 | 11920929201609625 |
| 25 | 59604644775585625 |
| 26 | 298023225097656250 |