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 | 3 |
| 3 | 7 |
| 4 | 20 |
| 5 | 67 |
| 6 | 255 |
| 7 | 1080 |
| 8 | 5017 |
| 9 | 25287 |
| 10 | 137122 |
| 11 | 794545 |
| 12 | 4892167 |
| 13 | 31858034 |
| 14 | 218543759 |
| 15 | 1573857867 |
| 16 | 11863100692 |
| 17 | 93345011951 |
| 18 | 764941675963 |
| 19 | 6514819011216 |
| 20 | 57556900440429 |
| 21 | 526593974392123 |
| 22 | 4981585554604074 |
| 23 | 48658721593531669 |
| 24 | 490110875149889635 |