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 | 14 |
| 3 | 43 |
| 4 | 132 |
| 5 | 402 |
| 6 | 1230 |
| 7 | 3755 |
| 8 | 11475 |
| 9 | 35054 |
| 10 | 107091 |
| 11 | 327180 |
| 12 | 999540 |
| 13 | 3053674 |
| 14 | 9329255 |
| 15 | 28501469 |
| 16 | 87074210 |
| 17 | 266018951 |
| 18 | 812707666 |
| 19 | 2482885810 |
| 20 | 7585415532 |
| 21 | 23174032657 |
| 22 | 70798497487 |
| 23 | 216295031546 |
| 24 | 660798311057 |
| 25 | 2018791013454 |