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 | 1 |
| 2 | 6 |
| 3 | 51 |
| 4 | 506 |
| 5 | 5481 |
| 6 | 62832 |
| 7 | 749398 |
| 8 | 9203634 |
| 9 | 115607310 |
| 10 | 1478314266 |
| 11 | 19180049928 |
| 12 | 251857119696 |
| 13 | 3340843549855 |
| 14 | 44700485049720 |
| 15 | 602574657427116 |
| 16 | 8175951659117794 |
| 17 | 111572030260242090 |
| 18 | 1530312970340384580 |
| 19 | 21085148778264281865 |
| 20 | 291705220704719165526 |