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 | 13 |
| 3 | 39 |
| 4 | 115 |
| 5 | 337 |
| 6 | 993 |
| 7 | 2919 |
| 8 | 8587 |
| 9 | 25257 |
| 10 | 74289 |
| 11 | 218511 |
| 12 | 642715 |
| 13 | 1890449 |
| 14 | 5560465 |
| 15 | 16355255 |
| 16 | 48106475 |
| 17 | 141497817 |
| 18 | 416194129 |
| 19 | 1224171199 |
| 20 | 3600711835 |
| 21 | 10590941633 |
| 22 | 31151630513 |
| 23 | 91627743527 |
| 24 | 269508954923 |
| 25 | 792719257161 |
| 26 | 2331662118065 |