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 | 4 |
| 3 | 17 |
| 4 | 68 |
| 5 | 273 |
| 6 | 1092 |
| 7 | 4369 |
| 8 | 17476 |
| 9 | 69905 |
| 10 | 279620 |
| 11 | 1118481 |
| 12 | 4473924 |
| 13 | 17895697 |
| 14 | 71582788 |
| 15 | 286331153 |
| 16 | 1145324612 |
| 17 | 4581298449 |
| 18 | 18325193796 |
| 19 | 73300775185 |
| 20 | 293203100740 |
| 21 | 1172812402961 |
| 22 | 4691249611844 |
| 23 | 18764998447377 |
| 24 | 75059993789508 |