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 | 5 |
| 2 | 22 |
| 3 | 103 |
| 4 | 504 |
| 5 | 2505 |
| 6 | 12506 |
| 7 | 62507 |
| 8 | 312508 |
| 9 | 1562509 |
| 10 | 7812510 |
| 11 | 39062511 |
| 12 | 195312512 |
| 13 | 976562513 |
| 14 | 4882812514 |
| 15 | 24414062515 |
| 16 | 122070312516 |
| 17 | 610351562517 |
| 18 | 3051757812518 |
| 19 | 15258789062519 |
| 20 | 76293945312520 |
| 21 | 381469726562521 |
| 22 | 1907348632812522 |
| 23 | 9536743164062523 |