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 | 3 |
| 3 | 13 |
| 4 | 66 |
| 5 | 330 |
| 6 | 1624 |
| 7 | 7973 |
| 8 | 39173 |
| 9 | 192539 |
| 10 | 946375 |
| 11 | 4651541 |
| 12 | 22862658 |
| 13 | 112371609 |
| 14 | 552314945 |
| 15 | 2714670141 |
| 16 | 13342810843 |
| 17 | 65580931949 |
| 18 | 322335276473 |
| 19 | 1584302440665 |
| 20 | 7786967198052 |
| 21 | 38273537040452 |
| 22 | 188117350476413 |
| 23 | 924611109563490 |
| 24 | 4544534046237850 |