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 | 17 |
| 2 | 137 |
| 3 | 4389 |
| 4 | 35119 |
| 5 | 561925 |
| 6 | 4495433 |
| 7 | 287708141 |
| 8 | 2301665843 |
| 9 | 36826655919 |
| 10 | 294613251551 |
| 11 | 9427624079025 |
| 12 | 75420992684203 |
| 13 | 1206735883132973 |
| 14 | 9653887065398089 |
| 15 | 1235697544380650237 |