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=Joerg A future computation would require a better algorithm to compute all numbers X so that (X^2+1) is smooth. =Dan Would someone kindly explain to me what this sentence means? I haven't the foggiest idea.

http://mathworld.wolfram.com/SmoothNumber.html (and see also the See Also links) "Smooth" is like the familiar idea of a "round" number (which RCS advocated as an alternative nomenclature here) I haven't been tracking this thread closely, but in context it seems he wants an algorithm using some pool of candidates {X | isSmooth(X^2+1)} or the like.