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 | 1 |
| 2 | 511 |
| 3 | 19682 |
| 4 | 261632 |
| 5 | 1953124 |
| 6 | 10057502 |
| 7 | 40353606 |
| 8 | 133955584 |
| 9 | 387400806 |
| 10 | 998046364 |
| 11 | 2357947690 |
| 12 | 5149441024 |
| 13 | 10604499372 |
| 14 | 20620692666 |
| 15 | 38441386568 |
| 16 | 68585259008 |
| 17 | 118587876496 |
| 18 | 197961811866 |
| 19 | 322687697778 |
| 20 | 510999738368 |