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 | 5 |
| 2 | 20 |
| 3 | 65 |
| 4 | 190 |
| 5 | 506 |
| 6 | 1265 |
| 7 | 2990 |
| 8 | 6765 |
| 9 | 14725 |
| 10 | 31027 |
| 11 | 63505 |
| 12 | 126730 |
| 13 | 247170 |
| 14 | 472295 |
| 15 | 885723 |
| 16 | 1633000 |
| 17 | 2963840 |
| 18 | 5302075 |
| 19 | 9358470 |
| 20 | 16313440 |
| 21 | 28107365 |
| 22 | 47902010 |
| 23 | 80803485 |
| 24 | 134992865 |
| 25 | 223474667 |
| 26 | 366772720 |
| 27 | 597049255 |
| 28 | 964375855 |
| 29 | 1546208695 |
| 30 | 2461649861 |
| 31 | 3892774130 |