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A179785 Values x for records of minima of the positive distance d between the seventh power of a positive integer x and the square of an integer y such that d = x^7 - y^2 (x <> k^2 and y <> k^7). 15

%I #10 Sep 08 2023 22:41:52

%S 2,3,6,8,10,14,18,20,28,30,39,55,59,88,239,255,257,374,387,477,1136,

%T 1221,9104,10959,35962,43783,96569,148544,183163,194933,313592,842163,

%U 1254392,1468637,1506412,2377393,2407523,4636475,5756417,6615968

%N Values x for records of minima of the positive distance d between the seventh power of a positive integer x and the square of an integer y such that d = x^7 - y^2 (x <> k^2 and y <> k^7).

%C Distance d is equal to 0 when x = k^2 and y = k^7.

%C For d values see A179784.

%C For y values see A179786.

%C Conjecture (_Artur Jasinski_): For any positive number x >= A179785(n), the distance d between the seventh power of x and the square of any y (such that x <> k^2 and y <> k^7) can't be less than A179784(n).

%t d = 7; max = 1000; vecd = Table[10^100, {n, 1, max}]; vecx = Table[10^100, {n, 1, max}]; vecy = Table[10^100, {n, 1, max}]; len = 1; Do[m = Floor[(n^d)^(1/2)]; k = n^d - m^2; If[k != 0, ile = 0; Do[If[vecd[[z]] < k, ile = ile + 1], {z, 1, len}]; len = ile + 1; vecd[[len]] = k; vecx[[len]] = n; vecy[[len]] = m], {n, 1, 10000000}]; dd = {}; xx = {}; yy = {}; Do[AppendTo[dd, vecd[[n]]]; AppendTo[xx, vecx[[n]]]; AppendTo[yy, vecy[[n]]], {n, 1, len}]; xx

%Y Cf. A179107, A179108, A179109, A179386, A179387, A179388, A179407, A179408, A179784, A179786.

%K nonn

%O 1,1

%A _Artur Jasinski_, Jul 27 2010

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