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) |
|---|---|
| 1 | 1 |
| 2 | 6 |
| 3 | 24 |
| 4 | 106 |
| 5 | 460 |
| 6 | 1934 |
| 7 | 7952 |
| 8 | 32274 |
| 9 | 130068 |
| 10 | 522262 |
| 11 | 2093080 |
| 12 | 8380442 |
| 13 | 33538076 |
| 14 | 134184990 |
| 15 | 536805408 |
| 16 | 2147352610 |
| 17 | 8589672484 |
| 18 | 34359214118 |
| 19 | 137437904936 |
| 20 | 549753716778 |
| 21 | 2199019061292 |
| 22 | 8796084633646 |
| 23 | 35184355311664 |
| 24 | 140737454800946 |
| 25 | 562949886312500 |
| 26 | 2251799679467574 |