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 | 19 |
| 3 | 73 |
| 4 | 281 |
| 5 | 1083 |
| 6 | 4175 |
| 7 | 16097 |
| 8 | 62065 |
| 9 | 239307 |
| 10 | 922711 |
| 11 | 3557761 |
| 12 | 13717913 |
| 13 | 52893147 |
| 14 | 203943935 |
| 15 | 786361409 |
| 16 | 3032030689 |
| 17 | 11690820555 |
| 18 | 45077144455 |
| 19 | 173807214241 |
| 20 | 670161078089 |
| 21 | 2583988659867 |
| 22 | 9963272432111 |
| 23 | 38416111919777 |
| 24 | 148123788152017 |
| 25 | 571131629935179 |