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 | 13 |
| 2 | 117 |
| 3 | 832 |
| 4 | 5109 |
| 5 | 28054 |
| 6 | 141401 |
| 7 | 664287 |
| 8 | 2943460 |
| 9 | 12404535 |
| 10 | 50050910 |
| 11 | 194348193 |
| 12 | 729316796 |
| 13 | 2654041235 |
| 14 | 9393084103 |
| 15 | 32409549367 |
| 16 | 109246771179 |
| 17 | 360409934599 |
| 18 | 1165521592456 |
| 19 | 3699803142334 |