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 | 1 |
| 1 | 2 |
| 2 | 6 |
| 3 | 20 |
| 4 | 79 |
| 5 | 284 |
| 6 | 1237 |
| 7 | 4542 |
| 8 | 20626 |
| 9 | 76406 |
| 10 | 354080 |
| 11 | 1317964 |
| 12 | 6173634 |
| 13 | 23051344 |
| 14 | 108628550 |
| 15 | 406513364 |
| 16 | 1922354351 |
| 17 | 7206349304 |
| 18 | 34147706833 |
| 19 | 128187589014 |
| 20 | 608151037123 |
| 21 | 2285559568866 |
| 22 | 10850577045131 |
| 23 | 40817923301712 |
| 24 | 193850277807569 |
| 25 | 729825857819924 |
| 26 | 3466587141136257 |