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 | 3 |
| 2 | 25 |
| 3 | 413 |
| 4 | 10746 |
| 5 | 387607 |
| 6 | 17981769 |
| 7 | 1022586105 |
| 8 | 68964092542 |
| 9 | 5384626548491 |
| 10 | 477951767068986 |
| 11 | 47546350648784341 |
| 12 | 5240644323742274500 |
| 13 | 634033030117301108127 |
| 14 | 83540992651137240168361 |
| 15 | 11908866726507685451458545 |