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 | 19 |
| 2 | 145 |
| 3 | 715 |
| 4 | 2695 |
| 5 | 8437 |
| 6 | 23023 |
| 7 | 56485 |
| 8 | 127270 |
| 9 | 267410 |
| 10 | 529958 |
| 11 | 999362 |
| 12 | 1805570 |
| 13 | 3142790 |
| 14 | 5293970 |
| 15 | 8662214 |
| 16 | 13810511 |
| 17 | 21511325 |
| 18 | 32807775 |
| 19 | 49088325 |
| 20 | 72177105 |
| 21 | 104442195 |
| 22 | 148924425 |
| 23 | 209489475 |
| 24 | 291006300 |
| 25 | 399555156 |
| 26 | 542668764 |
| 27 | 729610420 |