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 | 15 |
| 3 | 1225 |
| 4 | 2145 |
| 5 | 99225 |
| 6 | 17955 |
| 7 | 893025 |
| 8 | 51975 |
| 9 | 4601025 |
| 10 | 315315 |
| 11 | 16769025 |
| 12 | 855855 |
| 13 | 12006225 |
| 14 | 2567565 |
| 15 | 108056025 |
| 16 | 6531525 |
| 17 | 385533225 |
| 18 | 11486475 |
| 19 | 225450225 |
| 20 | 16787925 |
| 21 | 1329696225 |
| 22 | 38513475 |
| 23 | 2701400625 |
| 24 | 77702625 |
| 25 | 6053618025 |
| 26 | 80405325 |
| 27 | 4846248225 |
| 28 | 101846745 |
| 29 | 2029052025 |
| 30 | 218243025 |