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 | 15 |
| 3 | 1549 |
| 4 | 11315839 |
| 5 | 268997909000 |
| 6 | 250057183645608263 |
| 7 | 431066310742284246294717 |
| 8 | 26767947592293738225917871688575 |
| 9 | 3047486118401281699024754722202652309976 |