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 | 1 |
| 2 | 5 |
| 3 | 27 |
| 4 | 145 |
| 5 | 796 |
| 6 | 4438 |
| 7 | 25034 |
| 8 | 142479 |
| 9 | 816620 |
| 10 | 4706977 |
| 11 | 27256963 |
| 12 | 158450461 |
| 13 | 924129535 |
| 14 | 5404960900 |
| 15 | 31689099660 |
| 16 | 186188338689 |
| 17 | 1096001511849 |
| 18 | 6462416487070 |
| 19 | 38161656273410 |
| 20 | 225653893420214 |
| 21 | 1335936968552131 |
| 22 | 7917871096128978 |
| 23 | 46975164555309282 |
| 24 | 278951672249192025 |