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 | 61 |
| 3 | 1513 |
| 4 | 33661 |
| 5 | 750751 |
| 6 | 17116009 |
| 7 | 398840401 |
| 8 | 9464040829 |
| 9 | 227864057851 |
| 10 | 5550936701311 |
| 11 | 136526608389601 |
| 12 | 3384729259165801 |
| 13 | 84478081828015513 |
| 14 | 2120572560190269841 |
| 15 | 53494979095639780513 |
| 16 | 1355345459896317255037 |
| 17 | 34469858667289041256051 |
| 18 | 879619727291950363099291 |