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 | 7 |
| 2 | 29 |
| 3 | 103 |
| 4 | 373 |
| 5 | 1407 |
| 6 | 5277 |
| 7 | 19639 |
| 8 | 73157 |
| 9 | 272943 |
| 10 | 1018157 |
| 11 | 3796839 |
| 12 | 14159317 |
| 13 | 52806751 |
| 14 | 196940221 |
| 15 | 734469911 |
| 16 | 2739138277 |
| 17 | 10215390607 |
| 18 | 38097452877 |
| 19 | 142081224135 |
| 20 | 529879903477 |
| 21 | 1976142458303 |
| 22 | 7369856791005 |
| 23 | 27485259393911 |
| 24 | 102503957075973 |
| 25 | 382279865222383 |
| 26 | 1425680525146477 |
| 27 | 5316955307198503 |