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 | -13 |
| 2 | 183 |
| 3 | -2561 |
| 4 | 35855 |
| 5 | -501969 |
| 6 | 7027567 |
| 7 | -98385937 |
| 8 | 1377403119 |
| 9 | -19283643665 |
| 10 | 269971011311 |
| 11 | -3779594158353 |
| 12 | 52914318216943 |
| 13 | -740800455037201 |
| 14 | 10371206370520815 |
| 15 | -145196889187291409 |
| 16 | 2032756448622079727 |
| 17 | -28458590280709116177 |
| 18 | 398420263929927626479 |