A218386 a(n) = A215929(n) - (-1)^Fibonacci(n+1)*A218086(n).
2, 5, 19, 257, 196687
Offset: 0
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.