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 | 1 |
| 2 | 5 |
| 3 | 20 |
| 4 | 74 |
| 5 | 278 |
| 6 | 1049 |
| 7 | 3980 |
| 8 | 15170 |
| 9 | 58052 |
| 10 | 222914 |
| 11 | 858512 |
| 12 | 3314960 |
| 13 | 12829070 |
| 14 | 49748705 |
| 15 | 193259660 |
| 16 | 751954250 |
| 17 | 2929965020 |
| 18 | 11431262390 |
| 19 | 44651369720 |
| 20 | 174597927740 |
| 21 | 683388447260 |
| 22 | 2677230376490 |
| 23 | 10496941482680 |
| 24 | 41188078562324 |