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 | 3 |
| 2 | 12 |
| 3 | 63 |
| 4 | 421 |
| 5 | 3472 |
| 6 | 34380 |
| 7 | 399463 |
| 8 | 5344770 |
| 9 | 81097517 |
| 10 | 1377986373 |
| 11 | 25947738574 |
| 12 | 536726987593 |
| 13 | 12104879913657 |
| 14 | 295754724799758 |
| 15 | 7784814503249896 |
| 16 | 219682110287448760 |
| 17 | 6617691928179590112 |