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) |
|---|---|
| 0 | 2 |
| 1 | 5 |
| 2 | 15 |
| 3 | 50 |
| 4 | 177 |
| 5 | 650 |
| 6 | 2445 |
| 7 | 9350 |
| 8 | 36177 |
| 9 | 141170 |
| 10 | 554325 |
| 11 | 2186750 |
| 12 | 8656377 |
| 13 | 34355690 |
| 14 | 136617405 |
| 15 | 544061750 |
| 16 | 2169039777 |
| 17 | 8654570210 |
| 18 | 34553579685 |
| 19 | 138020346350 |
| 20 | 551499730377 |
| 21 | 2204254480730 |
| 22 | 8811785649165 |
| 23 | 35231447872550 |
| 24 | 140878711512177 |
| 25 | 563373614503250 |