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 | 121 |
| 3 | 553 |
| 4 | 2399 |
| 5 | 34867 |
| 6 | 257733 |
| 7 | 1744887 |
| 8 | 16192521 |
| 9 | 132651622 |
| 10 | 1038281076 |
| 11 | 8774615462 |
| 12 | 72803921204 |
| 13 | 594525068675 |
| 14 | 4940133605905 |
| 15 | 40989589283304 |
| 16 | 338552166728150 |
| 17 | 2806660250827517 |
| 18 | 23275769947149983 |
| 19 | 192804453727767520 |