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 | 2 |
| 2 | 13 |
| 3 | 114 |
| 4 | 1150 |
| 5 | 12586 |
| 6 | 145299 |
| 7 | 1741844 |
| 8 | 21475146 |
| 9 | 270570300 |
| 10 | 3468352701 |
| 11 | 45089941936 |
| 12 | 593082894768 |
| 13 | 7878407177270 |
| 14 | 105542811922950 |
| 15 | 1424267372100456 |
| 16 | 19343105144742098 |
| 17 | 264182048662182420 |
| 18 | 3626176386241346070 |
| 19 | 49995713597946235350 |
| 20 | 692084935397470961346 |