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 | 3 |
| 2 | 23 |
| 3 | 165 |
| 4 | 1218 |
| 5 | 9247 |
| 6 | 71688 |
| 7 | 564759 |
| 8 | 4506005 |
| 9 | 36324407 |
| 10 | 295341956 |
| 11 | 2418783687 |
| 12 | 19932773439 |
| 13 | 165151576215 |
| 14 | 1374850036253 |
| 15 | 11493442158373 |
| 16 | 96443092570534 |
| 17 | 811995039077311 |
| 18 | 6857352935798972 |
| 19 | 58071096513853991 |
| 20 | 493014496906492215 |
| 21 | 4195315394988567303 |