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 | 7 |
| 3 | 28 |
| 4 | 115 |
| 5 | 497 |
| 6 | 2086 |
| 7 | 9091 |
| 8 | 40575 |
| 9 | 172996 |
| 10 | 760155 |
| 11 | 3348129 |
| 12 | 14520438 |
| 13 | 63606819 |
| 14 | 278902951 |
| 15 | 1216232548 |
| 16 | 5321761651 |
| 17 | 23294489377 |
| 18 | 101772095142 |
| 19 | 445140686771 |
| 20 | 1947282645119 |
| 21 | 8512898474820 |
| 22 | 37229821964539 |
| 23 | 162827989419377 |