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 | 21 |
| 4 | 76 |
| 5 | 282 |
| 6 | 1065 |
| 7 | 4074 |
| 8 | 15732 |
| 9 | 61193 |
| 10 | 239406 |
| 11 | 941064 |
| 12 | 3713701 |
| 13 | 14703896 |
| 14 | 58383138 |
| 15 | 232383841 |
| 16 | 926943678 |
| 17 | 3704410890 |
| 18 | 14828984641 |
| 19 | 59450138412 |
| 20 | 238659074286 |
| 21 | 959247218253 |
| 22 | 3859777477944 |
| 23 | 15546444564846 |
| 24 | 62675854384977 |
| 25 | 252893414725842 |
| 26 | 1021208266423260 |