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 | 1 |
| 2 | 3 |
| 3 | 13 |
| 4 | 111 |
| 5 | 1381 |
| 6 | 22383 |
| 7 | 461413 |
| 8 | 12163791 |
| 9 | 420626821 |
| 10 | 19880808303 |
| 11 | 1337330559973 |
| 12 | 130909732781391 |
| 13 | 18649561895661061 |
| 14 | 3830195104867879023 |
| 15 | 1124247654215697637093 |
| 16 | 469367653568553278229711 |
| 17 | 278046313987470874905216901 |
| 18 | 233462156432002170491075384943 |