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 | 3 |
| 1 | 17 |
| 2 | 117 |
| 3 | 863 |
| 4 | 6513 |
| 5 | 49607 |
| 6 | 379857 |
| 7 | 2920823 |
| 8 | 22542273 |
| 9 | 174571847 |
| 10 | 1356218097 |
| 11 | 10567263383 |
| 12 | 82560768033 |
| 13 | 646644832487 |
| 14 | 5076269600337 |
| 15 | 39931933631543 |
| 16 | 314707907345793 |
| 17 | 2484430327803527 |
| 18 | 19642812107654577 |
| 19 | 155514083261753303 |