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 | 30 |
| 3 | 340 |
| 4 | 2530 |
| 5 | 14595 |
| 6 | 70737 |
| 7 | 301070 |
| 8 | 1157820 |
| 9 | 4100785 |
| 10 | 13563010 |
| 11 | 42321840 |
| 12 | 125586440 |
| 13 | 356621070 |
| 14 | 973989030 |
| 15 | 2569116330 |
| 16 | 6567458520 |
| 17 | 16317741975 |
| 18 | 39504992395 |
| 19 | 93390535840 |
| 20 | 215983566780 |
| 21 | 489454806785 |
| 22 | 1088433416785 |
| 23 | 2378160809610 |
| 24 | 5111208572940 |
| 25 | 10816601842950 |