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 | 1 |
| 1 | 1 |
| 2 | 5 |
| 3 | 27 |
| 4 | 502 |
| 5 | 2375 |
| 6 | 95435 |
| 7 | 1287965 |
| 8 | 29960476 |
| 9 | 262426878 |
| 10 | 28184365650 |
| 11 | 303473091075 |
| 12 | 46437880787562 |
| 13 | 593196287807409 |
| 14 | 8172332906336599 |
| 15 | 241563260379065625 |
| 16 | 64808657541894257992 |
| 17 | 1087738506483388123364 |
| 18 | 367580830209839294339148 |
| 19 | 6906008426663826491899602 |
| 20 | 136666305828261517346022452 |