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 | 129 |
| 3 | 3154 |
| 4 | 44024 |
| 5 | 745178 |
| 6 | 11771298 |
| 7 | 190540884 |
| 8 | 3057290265 |
| 9 | 49208639399 |
| 10 | 791176762937 |
| 11 | 12725363193829 |
| 12 | 204647839919537 |
| 13 | 3291296999329711 |
| 14 | 52931964429099939 |
| 15 | 851279732514835940 |
| 16 | 13690693829364308175 |