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) |
|---|---|
| 2 | 1 |
| 3 | 3 |
| 4 | 11 |
| 5 | 35 |
| 6 | 132 |
| 7 | 471 |
| 8 | 1806 |
| 9 | 7042 |
| 10 | 28494 |
| 11 | 118662 |
| 12 | 510517 |
| 13 | 2262738 |
| 14 | 10337474 |
| 15 | 48625631 |
| 16 | 235357470 |
| 17 | 1171163995 |
| 18 | 5986424739 |
| 19 | 31403695142 |
| 20 | 168913667164 |
| 21 | 930739116386 |
| 22 | 5249162406890 |
| 23 | 30275048671498 |
| 24 | 178428441191289 |
| 25 | 1073737691984694 |
| 26 | 6592909590432719 |