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 | 2 |
| 2 | 6 |
| 3 | 40 |
| 4 | 581 |
| 5 | 17954 |
| 6 | 1376484 |
| 7 | 275524246 |
| 8 | 147627941386 |
| 9 | 213261119287108 |
| 10 | 836129127802137203 |
| 11 | 8961301472286672235092 |
| 12 | 264386586050074867407985650 |
| 13 | 21609889100291959988235675761782 |
| 14 | 4921292113269596022145447106163528469 |
| 15 | 3138303995382684496665239674427115214538716 |