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 | 19 |
| 2 | 140 |
| 3 | 860 |
| 4 | 4572 |
| 5 | 22183 |
| 6 | 100362 |
| 7 | 432048 |
| 8 | 1791740 |
| 9 | 7225068 |
| 10 | 28510387 |
| 11 | 110629661 |
| 12 | 423640742 |
| 13 | 1605361751 |
| 14 | 6032626211 |
| 15 | 22517083366 |
| 16 | 83589139136 |
| 17 | 308933515758 |
| 18 | 1137661210293 |
| 19 | 4177146453272 |
| 20 | 15300167480847 |
| 21 | 55930646132694 |