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 | 21 |
| 2 | 239 |
| 3 | 2999 |
| 4 | 36787 |
| 5 | 454385 |
| 6 | 5598861 |
| 7 | 69050253 |
| 8 | 851302029 |
| 9 | 10496827403 |
| 10 | 129422885699 |
| 11 | 1595777230271 |
| 12 | 19675706193157 |
| 13 | 242599324206721 |
| 14 | 2991220223776445 |
| 15 | 36881397137844409 |
| 16 | 454743263319217787 |
| 17 | 5606930966068061311 |
| 18 | 69132797971282998447 |