Here is another typical example. This proves that fights with me. Because of the method of solution. http://mathoverflow.net/questions/31118/integer-polynomials-taking-square-values Ask for exactly the formula for solving the equation. I wrote a formula linking this equation with equation Pell. I wrote the formula in General. You can substitute any of the coefficients. These formulas look quite simple. For these equations we use the standard approach. For a private quadratic form: $$Y^2=aX^2+bX+1$$ Using solutions of Pell's equation: $$p^2-as^2=1$$ Solutions can be expressed through them is quite simple. $$Y=p^2+bps+as^2$$ $$X=2ps+bs^2$$ $p,s$ - these numbers can have any sign. Finding solutions of equations Pell - standard procedure. Most interesting is that all the examples which lead shows the relationship of this equation with Equation Pell. What is the point to write thousands of sequences ? If there's one formula that describes them all. Bring as an example the numbers, and it is good. When I write a formula - it require to remove!