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 | 2 |
| 3 | 7 |
| 4 | 23 |
| 5 | 84 |
| 6 | 331 |
| 7 | 1367 |
| 8 | 5812 |
| 9 | 25331 |
| 10 | 112804 |
| 11 | 511045 |
| 12 | 2348042 |
| 13 | 10919414 |
| 14 | 51313463 |
| 15 | 243332340 |
| 16 | 1163105227 |
| 17 | 5598774334 |
| 18 | 27119990519 |
| 19 | 132107355553 |
| 20 | 646793104859 |
| 21 | 3181256110699 |
| 22 | 15712610146876 |
| 23 | 77903855239751 |
| 24 | 387609232487489 |
| 25 | 1934788962992123 |