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 | 21 |
| 1 | 883 |
| 2 | 37107 |
| 3 | 1559377 |
| 4 | 65530941 |
| 5 | 2753858899 |
| 6 | 115727604699 |
| 7 | 4863313256257 |
| 8 | 204374884367493 |
| 9 | 8588608456690963 |
| 10 | 360925930065387939 |
| 11 | 15167477671202984401 |
| 12 | 637394988120590732781 |
| 13 | 26785756978736013761203 |